chore(deps): update actions/checkout action to v6 (#490)

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

Author: renovate[bot]

.github/workflows/release.yaml

@@ -17,7 +17,7 @@ jobs:
       - test
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Set up Python
         uses: actions/setup-python@v6

.github/workflows/test_and_build.yml

@@ -15,7 +15,7 @@ jobs:
         python-version: ["3.10", "3.11", "3.12"]
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v6