Bump actions/checkout from 5 to 6 in the github_actions group

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] <[email protected]>

Author: dependabot[bot]

.github/workflows/deploy-website.yaml

@@ -19,7 +19,7 @@ jobs:
       run:
         working-directory: website
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Use Node.js
         uses: actions/setup-node@v6
         with:

.github/workflows/pytest.yml

@@ -17,7 +17,7 @@ jobs:
         python-version: ["3.11"]
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v6
         with: