Bump codecov/codecov-action from 3 to 4 (#31)

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from 3 to 4.
- [Release notes](https://github.com/codecov/codecov-action/releases)
- [Changelog](https://github.com/codecov/codecov-action/blob/main/CHANGELOG.md)
- [Commits](codecov/codecov-action@v3...v4)

---
updated-dependencies:
- dependency-name: codecov/codecov-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/test.yaml

@@ -46,15 +46,15 @@ jobs:
 
       - name: Upload code coverage (unit)
         if: matrix.go-version == env.GO_LATEST_VERSION
-        uses: codecov/codecov-action@v3
+        uses: codecov/codecov-action@v4
         with:
           files: ./unit.coverprofile
           flags: unittests-${{ runner.os }}
 
 
       - name: Upload code coverage (features)
         if: matrix.go-version == env.GO_LATEST_VERSION
-        uses: codecov/codecov-action@v3
+        uses: codecov/codecov-action@v4
         with:
           files: ./features.coverprofile
           flags: features-${{ runner.os }}