Bump ajv from 6.12.6 to 8.12.0

Bumps [ajv](https://github.com/ajv-validator/ajv) from 6.12.6 to 8.12.0.
- [Release notes](https://github.com/ajv-validator/ajv/releases)
- [Commits](ajv-validator/ajv@v6.12.6...v8.12.0)

---
updated-dependencies:
- dependency-name: ajv
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -13,7 +13,7 @@
     "applicationId": "amzn1.echo-sdk-ams.app.999999-d0ed-9999-ad00-999999d00ebe"
   },
   "devDependencies": {
-    "ajv": "^6.12.6",
+    "ajv": "^8.12.0",
     "aws-sdk": "^2.1453.0",
     "chai": "^4.3.8",
     "chai-as-promised": "^7.1.1",