Run linting and testing GitHub workflows on PRs

.github/workflows/shellcheck.yml

@@ -3,7 +3,10 @@ name: shellcheck
 permissions:
   checks: write
 
-on: [push]
+on:
+  push:
+    branches: [main]
+  pull_request:
 
 jobs:
   lint:

.github/workflows/test-monorepo.yml

@@ -1,5 +1,8 @@
 name: test-monorepo
-on: [push]
+on:
+  push:
+    branches: [main]
+  pull_request:
 jobs:
   # test npm publish dry-run
   checkout_publish_skunkworks_dry_run:

.github/workflows/test-polyrepo.yml

@@ -1,5 +1,8 @@
 name: test-polyrepo
-on: [push]
+on:
+  push:
+    branches: [main]
+  pull_request:
 jobs:
   # test npm publish dry-run
   checkout_publish_controllers_dry_run:

.github/workflows/test.yml

@@ -1,5 +1,8 @@
 name: test
-on: [push]
+on:
+  push:
+    branches: [main]
+  pull_request:
 jobs:
   test:
     runs-on: ubuntu-20.04