chore(deps): update actions/checkout action to v6 (#2916)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/test.yml

@@ -179,7 +179,7 @@ jobs:
         python-version: ['3.12']
       fail-fast: false
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Install uv
         uses: astral-sh/setup-uv@v7
       - name: Set up Python ${{ matrix.python-version }}