chore: pin third-party GitHub Actions to commit SHAs (#374)

Author: pkaeding

.github/actions/setup/action.yml

@@ -12,7 +12,7 @@ inputs:
 runs:
   using: composite
   steps:
-    - uses: ruby/setup-ruby@v1
+    - uses: ruby/setup-ruby@319994f95fa847cf3fb3cd3dbe89f6dcde9f178f # v1.295.0
       with:
         ruby-version: ${{ inputs.version }}
         bundler: 2

.github/workflows/release-please.yml

@@ -18,7 +18,7 @@ jobs:
       upload-tag-name: ${{ steps.release.outputs.tag_name }}
 
     steps:
-      - uses: googleapis/release-please-action@v4
+      - uses: googleapis/release-please-action@16a9c90856f42705d54a6fda1823352bdc62cf38 # v4.4.0
         id: release
 
   build-ruby-gem: