ci: close conflicting prs created by aqua-registry app

.github/workflows/close-conflicting-pr.yaml

@@ -0,0 +1,39 @@
+---
+name: Close conflicting PRs created by aquaproj-aqua-registry
+on:
+  workflow_dispatch: {}
+  schedule:
+    - cron: "0 */1 * * *" # Hourly
+
+jobs:
+  rerun:
+    runs-on: ubuntu-24.04
+    timeout-minutes: 15
+    permissions:
+      pull-requests: write # To close pull requests
+    steps:
+      - run: |
+          set -eu
+
+          info() {
+              echo "[INFO] $*" >&2
+          }
+
+          bot=app/aquaproj-aqua-registry
+
+          info "searching pull requests"
+          numbers=$(gh -R "$GITHUB_REPOSITORY" pr list \
+            --json number,mergeable \
+            -S "author:$bot is:open" \
+            -L 100 \
+            -q '.[] | select(.mergeable == "CONFLICTING") | .number')
+
+          workflow_run_url=$GITHUB_SERVER_URL/$GITHUB_REPOSITORY/actions/runs/$GITHUB_RUN_ID
+
+          for number in $numbers; do
+              info "closing a pull request #$number"
+              gh -R "$GITHUB_REPOSITORY" pr close -d \
+                -c "[Workflow]($workflow_run_url) Close this pull request because this is created by app/aquaproj-aqua-registry and it has conflicts"
+          done
+        env:
+          GITHUB_TOKEN: ${{github.token}}