Bump actions/checkout from 5 to 6 in the actions group (#117)

Bumps the 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: actions
...

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

Author: dependabot[bot]

.github/workflows/check-for-updates.yml

@@ -36,7 +36,7 @@ jobs:
     if: needs.check-pr-exists.outputs.pr_exists == 'false'  # Run only if no PR exists
     steps:
       - name: Check out repository (shallow)
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           fetch-depth: 1  # Shallow clone to save time
 

.github/workflows/publish.yml

@@ -24,7 +24,7 @@ jobs:
     permissions:
       id-token: write
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - name: Set up Python
       uses: actions/setup-python@v6
       with:

.github/workflows/tests.yml

@@ -27,7 +27,7 @@ jobs:
     container:
       image: ${{ matrix.use-container && format('python:{0}', matrix.python-version) || '' }}
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - if: ${{ !matrix.use-container }}
       name: Set up Python ${{ matrix.python-version }} on ${{ matrix.os }} (non-containers)
       uses: actions/setup-python@v6
@@ -51,7 +51,7 @@ jobs:
       TOXENV: ${{ matrix.toxenv }}
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: ${{ matrix.toxenv }}
         uses: actions/setup-python@v6
         with: