[Backport 8.x] Use git recordings for pull request validation (elastic#3185)

Co-authored-by: Quentin Pradet <[email protected]>

Author: github-actions[bot]

.github/workflows/validate-pr.yml

@@ -59,7 +59,7 @@ jobs:
           else
             branch=$GITHUB_REF_NAME
           fi
-          node scripts/upload-recording/download.js --branch $branch
+          node scripts/upload-recording/download.js --branch $branch --git
           node scripts/clone-elasticsearch/index.js --branch $branch
         env:
           GCS_CREDENTIALS: ${{ secrets.GCS_CREDENTIALS }}