Upgrade GitHub Actions

.github/workflows/validate_links.yml

@@ -14,12 +14,12 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
 
       - name: Set up Python
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v4
         with:
-          python-version: '3.8'
+          python-version: '3.x'
 
       - name: Install dependencies
         run: python -m pip install -r scripts/requirements.txt