Build(deps): Bump codecov/codecov-action from 3 to 4 (#812)

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] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/run-pytest.yml

@@ -61,4 +61,4 @@ jobs:
     - name: Test with pytest
       run: |
         pytest --cov=flow --cov-config=pyproject.toml --cov-report=xml tests/ -v
-    - uses: codecov/codecov-action@v3
+    - uses: codecov/codecov-action@v4