newer setup python action

Author: davidkoski

.github/workflows/pull_request.yml

@@ -16,7 +16,7 @@ jobs:
         with:
           submodules: recursive
 
-      - uses: actions/setup-python@v3
+      - uses: actions/setup-python@v6
       - uses: pre-commit/action@v3.0.1
 
       - name: Clone swift-format