[actions] add "Require Allow Edits" action

Author: ljharb

.github/workflows/require-allow-edits.yml

@@ -0,0 +1,15 @@
+name: Require “Allow Edits”
+
+on: pull_request_target
+    types: [opened, synchronize, reopened, edited]
+
+jobs:
+  _:
+    name: "Require “Allow Edits”"
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: ljharb/require-allow-edits@main
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}