ci: run enforcer check only on release-please PRs

- Update enforcer job in ci.yaml to run only when PR is raised from release-please--branches--main and title does not end with SNAPSHOT
- Skips enforcer check on standard feature/bugfix PRs to eliminate 20+ minute CI turnaround time

Author: lqiu96

.github/workflows/ci.yaml

@@ -401,7 +401,10 @@ jobs:
         BASE_SHA: ${{ github.event.pull_request.base.sha || github.event.before }}
   enforcer:
     needs: bulk-filter
-    if: ${{ needs.bulk-filter.outputs.runnable == 'true' }}
+    if: |
+      needs.bulk-filter.outputs.runnable == 'true' &&
+      github.head_ref == 'release-please--branches--main' &&
+      !endsWith(github.event.pull_request.title, 'SNAPSHOT')
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4.4.0