Bump actions/checkout from 4 to 7

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 7.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v4...v7)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/ci.yml

@@ -17,7 +17,7 @@ jobs:
     name: Lint
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v7
 
       - name: Install system dependencies
         run: sudo apt-get update && sudo apt-get install -y libcairo2-dev
@@ -45,7 +45,7 @@ jobs:
       DATABASE_ENGINE: sqlite3
       DATABASE_NAME: db.sqlite3
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v7
 
       - name: Install system dependencies
         run: sudo apt-get update && sudo apt-get install -y libcairo2-dev
@@ -94,7 +94,7 @@ jobs:
           - platform: linux/arm64
             runner: ubuntu-24.04-arm
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v7
 
       - uses: docker/setup-buildx-action@v4