Bump actions/checkout from 4.2.0 to 4.2.1

Bumps [actions/checkout](https://github.com/actions/checkout) from 4.2.0 to 4.2.1.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v4.2.0...v4.2.1)

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

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

.github/workflows/docs.yaml

@@ -23,7 +23,7 @@ jobs:
     needs: docs
     runs-on: ubuntu-24.04
     steps:
-      - uses: actions/checkout@v4.2.0
+      - uses: actions/checkout@v4.2.1
       - uses: actions/setup-python@v5.2.0
         with:
           python-version: "3.12"

.github/workflows/tests.yaml

@@ -150,7 +150,7 @@ jobs:
     # We keep going when a job flagged as not stable fails.
     continue-on-error: ${{ matrix.state == 'unstable' }}
     steps:
-      - uses: actions/checkout@v4.2.0
+      - uses: actions/checkout@v4.2.1
 
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v5.2.0