ci: bump codecov/codecov-action from 6 to 7

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from 6 to 7.
- [Release notes](https://github.com/codecov/codecov-action/releases)
- [Changelog](https://github.com/codecov/codecov-action/blob/main/CHANGELOG.md)
- [Commits](codecov/codecov-action@v6...v7)

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

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

Author: dependabot[bot]

.github/workflows/unit.yml

@@ -21,7 +21,7 @@ jobs:
         run: go test -v -cover -coverprofile coverage.txt ./...
       - name: Upload coverage to Codecov
         if: ${{ !cancelled() }}
-        uses: codecov/codecov-action@v6
+        uses: codecov/codecov-action@v7
         env:
           OS: ${{ matrix.os }}
           GO: ${{ matrix.go }}