[llvm] Add GitHub workflow for check Python file formatting (PR #65482)

[Tom Stellard via llvm-commits]

================
@@ -0,0 +1,39 @@
+name: "Check Python Formatting"
+on:
+  pull_request:
+    # run on .py
+    paths:
+      - '**.py'
+
+jobs:
+  python_formatting:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Fetch LLVM sources
+        uses: actions/checkout at v4
+        with:
+          persist-credentials: false
+          fetch-depth: 2
----------------
tstellar wrote:

Why do we need `fetch-depth: 2` ?

https://github.com/llvm/llvm-project/pull/65482