Bump codecov/codecov-action from 5 to 6 (#1619)

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from 5 to 6.
- [Release notes](https://github.com/codecov/codecov-action/releases)
- [Changelog](https://github.com/codecov/codecov-action/blob/main/CHANGELOG.md)
- [Commits](codecov/codecov-action@v5...v6)

---
updated-dependencies:
- dependency-name: codecov/codecov-action
  dependency-version: '6'
  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>
Co-authored-by: Todd Leonhardt <todd.leonhardt@gmail.com>

Author: dependabot[bot]

.github/workflows/tests.yml

@@ -40,14 +40,14 @@ jobs:
 
       - name: Upload test results to Codecov
         if: ${{ !cancelled() }}
-        uses: codecov/codecov-action@v5
+        uses: codecov/codecov-action@v6
         with:
           flags: python${{ matrix.python-version }}
           name: codecov-umbrella-test-results
           report_type: test_results
           token: ${{ secrets.CODECOV_TOKEN }}
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v5
+        uses: codecov/codecov-action@v6
         with:
           env_vars: OS,PYTHON
           fail_ci_if_error: true