Bump codecov/codecov-action from 2 to 4

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from 2 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@v2...v4)

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

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/codecov.yml

@@ -38,4 +38,4 @@ jobs:
         coverage run setup.py test
 
     - name: Upload Coverage to Codecov
-      uses: codecov/codecov-action@v2
+      uses: codecov/codecov-action@v4