Bump actions/checkout from 2 to 4

Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v2...v4)

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

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/check.yml

@@ -15,7 +15,7 @@ jobs:
       matrix:
         python-version: [3.9, "3.10", 3.11, 3.12, 3.13]
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v5
         with:
@@ -30,21 +30,21 @@ jobs:
     runs-on: ubuntu-latest
     needs: check-and-test
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Test setuptools
         run: ./go test-setuptools
   release-readiness-docker-build:
     runs-on: ubuntu-latest
     needs: check-and-test
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Test docker build
         run: ./go test-docker-build
   codeql-analyse:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
         with:
           # We must fetch at least the immediate parents so that if this is
           # a pull request then we can checkout the head.