[APM] Migrate inspect API tests to be deployment-agnostic (#199963)

### How to test
Closes #198977
Part of #193245

This PR contains the changes to migrate `inspect` test folder to
deployment-agnostic testing strategy.

### How to test

- Serverless

```
node scripts/functional_tests_server --config x-pack/test/api_integration/deployment_agnostic/configs/serverless/oblt.serverless.config.ts
node scripts/functional_test_runner --config x-pack/test/api_integration/deployment_agnostic/configs/serverless/oblt.serverless.config.ts --grep="APM"
```

It's recommended to be run against
[MKI](https://github.com/crespocarlos/kibana/blob/main/x-pack/test_serverless/README.md#run-tests-on-mki)

- Stateful
```
node scripts/functional_tests_server --config x-pack/test/api_integration/deployment_agnostic/configs/stateful/oblt.stateful.config.ts
node scripts/functional_test_runner --config x-pack/test/api_integration/deployment_agnostic/configs/stateful/oblt.stateful.config.ts --grep="APM"
```

## Checks

- [ ] (OPTIONAL, only if a test has been unskipped) Run flaky test suite
- [x] local run for serverless
- [x] local run for stateful
- [x] MKI run for serverless

(cherry picked from commit bb68f92)

x-pack/test/api_integration/deployment_agnostic/apis/observability/apm/constants/archives_metadata.ts

@@ -0,0 +1,10 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import archivesMetadata from '../../../../../../apm_api_integration/common/fixtures/es_archiver/archives_metadata';
+
+export default archivesMetadata;

x-pack/test/api_integration/deployment_agnostic/apis/observability/apm/index.ts

@@ -26,6 +26,7 @@ export default function apmApiIntegrationTests({
     loadTestFile(require.resolve('./observability_overview'));
     loadTestFile(require.resolve('./latency'));
     loadTestFile(require.resolve('./infrastructure'));
+    loadTestFile(require.resolve('./inspect'));
     loadTestFile(require.resolve('./service_groups'));
   });
 }

x-pack/test/api_integration/deployment_agnostic/apis/observability/apm/inspect/index.ts

@@ -0,0 +1,14 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import { DeploymentAgnosticFtrProviderContext } from '../../../../ftr_provider_context';
+
+export default function ({ loadTestFile }: DeploymentAgnosticFtrProviderContext) {
+  describe('inspect', () => {
+    loadTestFile(require.resolve('./inspect.spec.ts'));
+  });
+}

x-pack/test/api_integration/deployment_agnostic/apis/observability/apm/inspect/inspect.spec.ts

@@ -0,0 +1,94 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import expect from '@kbn/expect';
+
+import { DeploymentAgnosticFtrProviderContext } from '../../../../ftr_provider_context';
+import { ARCHIVER_ROUTES } from '../constants/archiver';
+import archives_metadata from '../constants/archives_metadata';
+
+export default function inspectFlagTests({ getService }: DeploymentAgnosticFtrProviderContext) {
+  const apmApiClient = getService('apmApi');
+  const esArchiver = getService('esArchiver');
+
+  const archiveName = '8.0.0';
+  const metadata = archives_metadata['apm_8.0.0'];
+
+  describe('Inspect feature', () => {
+    before(async () => {
+      await esArchiver.load(ARCHIVER_ROUTES[archiveName]);
+    });
+    after(async () => {
+      await esArchiver.unload(ARCHIVER_ROUTES[archiveName]);
+    });
+
+    describe('when omitting `_inspect` query param', () => {
+      it('returns response without `_inspect`', async () => {
+        const { status, body } = await apmApiClient.readUser({
+          endpoint: 'GET /internal/apm/environments',
+          params: {
+            query: {
+              start: metadata.start,
+              end: metadata.end,
+            },
+          },
+        });
+
+        expect(status).to.be(200);
+        expect(body._inspect).to.be(undefined);
+      });
+    });
+
+    describe('when passing `_inspect` as query param', () => {
+      describe('elasticsearch calls made with end-user auth are returned', () => {
+        it('for environments', async () => {
+          const { status, body } = await apmApiClient.readUser({
+            endpoint: 'GET /internal/apm/environments',
+            params: {
+              query: {
+                start: metadata.start,
+                end: metadata.end,
+                _inspect: true,
+              },
+            },
+          });
+          expect(status).to.be(200);
+          expect(body._inspect).not.to.be.empty();
+
+          // @ts-expect-error
+          expect(Object.keys(body._inspect[0])).to.eql([
+            'id',
+            'json',
+            'name',
+            'response',
+            'startTime',
+            'stats',
+            'status',
+          ]);
+        });
+      });
+
+      describe('elasticsearch calls made with internal user should not leak internal queries', () => {
+        it('for custom links', async () => {
+          const { status, body } = await apmApiClient.readUser({
+            endpoint: 'GET /internal/apm/settings/custom_links',
+            params: {
+              query: {
+                'service.name': 'opbeans-node',
+                'transaction.type': 'request',
+                _inspect: true,
+              },
+            },
+          });
+
+          expect(status).to.be(200);
+          expect(body._inspect).to.eql([]);
+        });
+      });
+    });
+  });
+}

x-pack/test/apm_api_integration/tests/inspect/inspect.spec.ts

@@ -8,79 +8,15 @@
 import expect from '@kbn/expect';
 import { FtrProviderContext } from '../../common/ftr_provider_context';
 
-import archives_metadata from '../../common/fixtures/es_archiver/archives_metadata';
-
 export default function inspectFlagTests({ getService }: FtrProviderContext) {
   const registry = getService('registry');
   const apmApiClient = getService('apmApiClient');
 
   const archiveName = 'apm_8.0.0';
-  const metadata = archives_metadata[archiveName];
 
   registry.when('Inspect feature', { config: 'trial', archives: [archiveName] }, () => {
-    describe('when omitting `_inspect` query param', () => {
-      it('returns response without `_inspect`', async () => {
-        const { status, body } = await apmApiClient.readUser({
-          endpoint: 'GET /internal/apm/environments',
-          params: {
-            query: {
-              start: metadata.start,
-              end: metadata.end,
-            },
-          },
-        });
-
-        expect(status).to.be(200);
-        expect(body._inspect).to.be(undefined);
-      });
-    });
-
     describe('when passing `_inspect` as query param', () => {
-      describe('elasticsearch calls made with end-user auth are returned', () => {
-        it('for environments', async () => {
-          const { status, body } = await apmApiClient.readUser({
-            endpoint: 'GET /internal/apm/environments',
-            params: {
-              query: {
-                start: metadata.start,
-                end: metadata.end,
-                _inspect: true,
-              },
-            },
-          });
-          expect(status).to.be(200);
-          expect(body._inspect).not.to.be.empty();
-
-          // @ts-expect-error
-          expect(Object.keys(body._inspect[0])).to.eql([
-            'id',
-            'json',
-            'name',
-            'response',
-            'startTime',
-            'stats',
-            'status',
-          ]);
-        });
-      });
-
       describe('elasticsearch calls made with internal user should not leak internal queries', () => {
-        it('for custom links', async () => {
-          const { status, body } = await apmApiClient.readUser({
-            endpoint: 'GET /internal/apm/settings/custom_links',
-            params: {
-              query: {
-                'service.name': 'opbeans-node',
-                'transaction.type': 'request',
-                _inspect: true,
-              },
-            },
-          });
-
-          expect(status).to.be(200);
-          expect(body._inspect).to.eql([]);
-        });
-
         it('for agent configs', async () => {
           const { status, body } = await apmApiClient.readUser({
             endpoint: 'GET /api/apm/settings/agent-configuration 2023-10-31',