Bump actions/checkout from 5 to 6 in the github-actions group (#676)

Bumps the github-actions group with 1 update: [actions/checkout](https://github.com/actions/checkout).


Updates `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
  dependency-group: github-actions
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/main.yml

@@ -28,7 +28,7 @@ jobs:
         - '3.14'
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
 
     - uses: actions/setup-python@v6
       with:
@@ -57,7 +57,7 @@ jobs:
     runs-on: ubuntu-24.04
     needs: tests
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - uses: actions/setup-python@v6
         with: