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](https://github.com/actions/checkout/compare/v2...v4)

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

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

.github/workflows/build-test.yaml

@@ -13,7 +13,7 @@ jobs:
   backend:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
         with:
           path: ./
 
@@ -67,7 +67,7 @@ jobs:
   frontend:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
         with:
           path: ./
 

.github/workflows/sonar.yaml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     if: github.event.workflow_run.conclusion == 'success'
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           repository: ${{ github.event.workflow_run.head_repository.full_name }}
           ref: ${{ github.event.workflow_run.head_branch }}