Bump actions/checkout from 5 to 6 (#8)

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] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/auto-release.yml

@@ -19,7 +19,7 @@ jobs:
         shell: bash
     steps:
     - name: Checkout source
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         # Fetch all history for all branches and tags
         fetch-depth: 0

.github/workflows/python-publish.yml

@@ -14,7 +14,7 @@ jobs:
 
     steps:
     - name: Checkout source
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
     - name: Set up Python
       uses: actions/setup-python@v6
       with: