build(deps): bump actions/checkout from 6.0.3 to 7.0.0

Bumps [actions/checkout](https://github.com/actions/checkout) from 6.0.3 to 7.0.0.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v6.0.3...v7.0.0)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: 7.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -7,7 +7,7 @@ jobs:
     if: github.event_name == 'push' || github.event.pull_request.head.repo.full_name != github.repository
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6.0.3
+      - uses: actions/checkout@v7.0.0
       - uses: actions/setup-python@v6
         with:
           python-version: '3.11'
@@ -74,7 +74,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       # Build the images and start the containers.
-      - uses: actions/checkout@v6.0.3
+      - uses: actions/checkout@v7.0.0
       - name: Create .env file
         run: |
           echo "DJANGO_ENV=production" >> .env
@@ -108,7 +108,7 @@ jobs:
       # - run: docker compose -f docker-compose.test.yaml logs app
 
       # Test the images.
-      - uses: actions/checkout@v6.0.3
+      - uses: actions/checkout@v7.0.0
         with:
           repository: open-contracting/spoonbill-test
           path: test