ci: Fix unknown flag --pr error in manual workflow cancellation script

Author: arpittkhandelwal

.github/workflows/cancel-workflows.yml

@@ -54,8 +54,11 @@ jobs:
         run: |
           echo "Cancelling runs for PR #$PR_NUMBER..."
 
-          # Get all runs for the PR that are NOT completed, excluding this current run
-          RUN_IDS=$(gh run list --pr "$PR_NUMBER" --limit 200 --json databaseId,status --jq '.[] | select(.status != "completed" and .databaseId != (env.CURRENT_RUN_ID | tonumber)) | .databaseId')
+          # gh run list doesn't have a --pr flag, so we get the branch name first
+          PR_BRANCH=$(gh pr view "$PR_NUMBER" --json headRefName -q .headRefName)
+
+          # Get all runs for the PR branch that are NOT completed, excluding this current run
+          RUN_IDS=$(gh run list --branch "$PR_BRANCH" --limit 200 --json databaseId,status --jq '.[] | select(.status != "completed" and .databaseId != (env.CURRENT_RUN_ID | tonumber)) | .databaseId')
 
           if [ -z "$RUN_IDS" ]; then
             echo "No active runs found to cancel."