Bump GitHub Actions

Author: hugovk

.github/workflows/pythonpackage.yml

@@ -18,7 +18,7 @@ jobs:
         python-version: ["3.7", "3.8", "3.9", "3.10", "3.11"]
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
       with:
         fetch-depth: 1000
     - name: Set up Python ${{ matrix.python-version }}