feat(workflow): Create workflow that cleans up and closes PRS

Konflux continues to generate PRs for old release branches. This is
becacause the renovate config is on main and the older release branches
cannot get these changes merged, or a release will occur.

This workflow will auto-close those PRs and any new PRs generated for
release branches.

Signed-off-by: Bryan Ramos <bramos@redhat.com>

Author: CryptoRodeo

.github/workflows/cleanup-prs.yml

@@ -0,0 +1,39 @@
+name: Close release-* PRs
+
+on:
+  # Manual
+  workflow_dispatch:
+  schedule:
+    # Run daily at 2am UTC
+    - cron: "0 2 * * *"
+
+permission:
+  pull-requests: write
+  contents: read
+
+jobs:
+  close-release-prs:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Close PRs for release-* branches
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          echo "Finding open PRs that are for release branches"
+
+          prs=$(gh pr list \
+            --state open \
+            --json number,headRefName \
+            --jq '.[] | select(.headRefName | contains("release-")) | .number') 
+
+          if [ -z "$prs" ]; then
+            echo "No matching PRs found."
+            exit 0
+          fi
+
+          for pr in $prs; do
+            echo "Closing PR #$pr"
+            gh pr close "$pr" --comment "Automatically closing pull request for release branch."
+          done
+