ci: auto-close pull requests — not accepting PRs, use Discord

.github/workflows/close-prs.yml

@@ -0,0 +1,21 @@
+# GitHub has no switch to disable pull requests, so this closes them on arrival.
+# Uses pull_request_target (base-repo context, no PR code checked out) so it can
+# comment and close on PRs from forks.
+name: close-prs
+on:
+  pull_request_target:
+    types: [opened, reopened]
+permissions:
+  pull-requests: write
+jobs:
+  close:
+    runs-on: ubuntu-latest
+    steps:
+      - run: |
+          gh pr comment "$PR" --repo "$REPO" --body \
+            "Thanks for the interest! benilla is a solo project and isn't taking pull requests for now — please bring bug reports and ideas to the Discord instead: https://discord.gg/wJSJx467G4"
+          gh pr close "$PR" --repo "$REPO"
+        env:
+          GH_TOKEN: ${{ github.token }}
+          PR: ${{ github.event.pull_request.number }}
+          REPO: ${{ github.repository }}