chore: Update validate-pr action to latest version (#1120)

Updates the pinned SHA to pick up the bot allowlist fix, which
prevents trusted bots (dependabot, renovate, etc.) from being
closed by the PR validation workflow.

#skip-changelog

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: stephanie-anderson

.github/workflows/validate-pr.yml

@@ -10,7 +10,7 @@ jobs:
     permissions:
       pull-requests: write
     steps:
-      - uses: getsentry/github-workflows/validate-pr@4243265ac9cc3ee5b89ad2b30c3797ac8483d63a
+      - uses: getsentry/github-workflows/validate-pr@4ff40ada546d4a31b852a4279828b989a6193497
         with:
           app-id: ${{ vars.SDK_MAINTAINER_BOT_APP_ID }}
           private-key: ${{ secrets.SDK_MAINTAINER_BOT_PRIVATE_KEY }}