Bump codecov/codecov-action from 3 to 4 (#72)

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

.github/workflows/ci.yml

@@ -72,7 +72,7 @@ jobs:
           conda list
           cd /tmp
           pytest -vvv -r a --pyargs pyflct --cov-report=xml --cov=pyflct --cov-config=$GITHUB_WORKSPACE/setup.cfg $GITHUB_WORKSPACE/docs
-      - uses: codecov/codecov-action@v3
+      - uses: codecov/codecov-action@v4
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           files: ./coverage.xml