chore(deps): bump google-github-actions/deploy-appengine (#6951)

Bumps [google-github-actions/deploy-appengine](https://github.com/google-github-actions/deploy-appengine) from 1.2.2 to 1.2.6.
- [Release notes](https://github.com/google-github-actions/deploy-appengine/releases)
- [Changelog](https://github.com/google-github-actions/deploy-appengine/blob/main/CHANGELOG.md)
- [Commits](https://github.com/google-github-actions/deploy-appengine/compare/v1.2.2...v1.2.6)

---
updated-dependencies:
- dependency-name: google-github-actions/deploy-appengine
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/appengine_deploy.yml

@@ -42,7 +42,7 @@ jobs:
           path: _deploy/
 
       - name: Deploy to App Engine
-        uses: google-github-actions/deploy-appengine@v1.2.2
+        uses: google-github-actions/deploy-appengine@v1.2.6
         # For parameters see:
         # https://github.com/google-github-actions/deploy-appengine#inputs
         with: