lint: Upgrade GitHub Actions (#192)

* https://github.com/actions/checkout/releases
* https://github.com/actions/setup-python/releases

Co-authored-by: Michele Ceriotti <[email protected]>

Author: cclauss

.github/workflows/lint.yml

@@ -14,9 +14,9 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
     - name: Set up Python
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@v6
       with:
         python-version: "3.11"