Bump codecov/codecov-action from 4.5.0 to 4.6.0

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from 4.5.0 to 4.6.0.
- [Release notes](https://github.com/codecov/codecov-action/releases)
- [Changelog](https://github.com/codecov/codecov-action/blob/main/CHANGELOG.md)
- [Commits](codecov/codecov-action@v4.5.0...v4.6.0)

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

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

.github/workflows/ci.yaml

@@ -50,7 +50,7 @@ jobs:
         run: |
           pytest -n auto --cov=./ --cov-report=xml
       - name: Upload code coverage to Codecov
-        uses: codecov/codecov-action@v4.5.0
+        uses: codecov/codecov-action@v4.6.0
         with:
           file: ./coverage.xml
           flags: unittests
@@ -114,7 +114,7 @@ jobs:
         run: |
           python -m mypy --install-types --non-interactive --cobertura-xml-report mypy_report cf_xarray/
       - name: Upload mypy coverage to Codecov
-        uses: codecov/codecov-action@v4.5.0
+        uses: codecov/codecov-action@v4.6.0
         with:
           file: mypy_report/cobertura.xml
           flags: mypy