[llvm] workflows: Automatically make backport requests from merged PRs (PR #126993)

[Aiden Grossman via llvm-commits]

================
@@ -0,0 +1,29 @@
+name: PR Release Workflow
+
+permissions:
+  contents: read
+
+on:
+  pull_request:
+    types:
+      - milestoned
+      - closed
+
+jobs:
+  backport-commit:
+    runs-on: ubuntu-22.04
----------------
boomanaiden154 wrote:

`ubuntu-24.04` here? I want to start migrating things soonish, and it doesn't seem like anything will break for this workflow by bumping it.

https://github.com/llvm/llvm-project/pull/126993