chore: pin third-party GitHub Actions to commit SHAs (#238)

Author: pkaeding

.github/workflows/release-please.yml

@@ -23,7 +23,7 @@ jobs:
       LD_INCLUDE_INTEGRATION_TESTS: 1
 
     steps:
-      - uses: googleapis/release-please-action@v4
+      - uses: googleapis/release-please-action@16a9c90856f42705d54a6fda1823352bdc62cf38 # v4.4.0
         id: release
 
       - uses: actions/checkout@v4