[skip ci] #13019 Create remove-stale-branches.yaml (#13020)

* [skip ci] #13019 Create remove-stale-branches.yaml

* #13019 Update remove-stale-branches.yaml

Allow manual trigger.
Define stale as 6 months.

* #13019 Update remove-stale-branches.yaml

.github/workflows/remove-stale-branches.yaml

@@ -0,0 +1,15 @@
+name: "[internal] Remove Stale Branches"
+
+on:
+  schedule:
+    - cron: "0 0 * * *" # Runs every night at midnight
+  workflow_dispatch: # Allows manual trigger
+
+jobs:
+  remove-stale-branches:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: fpicalausa/[email protected]
+        with:
+          dry-run: true
+          days-before-branch-stale: 180 # Branches stale for ~6 months