Update actions/checkout action to v5

Author: renovate[bot]

.github/workflows/tests.yaml

@@ -13,7 +13,7 @@ jobs:
       matrix:
         python-version: ["3.11"]
     steps:
-      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v5
         with: