[llvm] [workflows] Delete user branches that are too long (PR #82845)

[Jessica Clarke via llvm-commits]

================
@@ -0,0 +1,33 @@
+name: User Branch Rules
+
+permissions:
+  contents: read
+
+
+on:
+  push:
+    branches:
+      - 'users/**'
+
+
+jobs:
+  user-branch-rules:
+    if: github.repository_owner == 'llvm'
+    permissions:
+      contents: write
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check branch length
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
+          MAX_BRANCH_LENGTH: 200
----------------
jrtc27 wrote:

But we already have "The title should be concise. Because all commits are emailed to the list with the first line as the subject, long titles are frowned upon. Short titles also look better in git log." in the developer policy, so this *shouldn't* be an issue if people actually adhere to our policy... (ha)

https://github.com/llvm/llvm-project/pull/82845