fix: fix for backport fix (#18119)

Author: ludamad

.github/workflows/backport.yml

@@ -60,7 +60,7 @@ jobs:
           # Kludge. We should write this in Python or not checkout history.
           # Bash has an ugly footgun with changing history while running the script.
           buffer_script=$(cat ./scripts/backport_to_staging.sh)
-          bash -c "$buffer_script" \
+          bash <(echo "$buffer_script") \
             ${{ github.event.pull_request.number }} \
             ${{ steps.extract-branch.outputs.target_branch }}