build(deps): bump actions/checkout from 5 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/mypy.yml

@@ -16,7 +16,7 @@ jobs:
     name: Python ${{ matrix.python-version }} sample
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - name: Set up Python
       uses: actions/setup-python@v6
       with:

.github/workflows/pytest.yml

@@ -16,7 +16,7 @@ jobs:
     name: Python ${{ matrix.python-version }} sample
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - name: Set up Python
       uses: actions/setup-python@v6
       with:

.github/workflows/release.yml

@@ -15,7 +15,7 @@ jobs:
     permissions:
       id-token: write  # IMPORTANT: this permission is mandatory for trusted publishing
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
       - name: Install Poetry