chore(deps): update actions/checkout digest to df4cb1c

Author: renovate[bot]

.github/workflows/ci.yaml

@@ -13,7 +13,7 @@ jobs:
       matrix:
         python-version: ["3.8", "3.9", "3.10", "3.11"]
     steps:
-      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6
         with:
@@ -33,7 +33,7 @@ jobs:
         os: [ubuntu-latest]
         python-version: ["3.8", "3.9", "3.10", "3.11"]
     steps:
-      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6
         with: