Bump codecov/codecov-action from 5 to 6

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>

Author: dependabot[bot]

.github/workflows/ci_conda.yml

@@ -38,7 +38,7 @@ jobs:
         pytest test/ --cov foam2dolfinx --cov-report xml --cov-report term
     
     - name: Upload to codecov
-      uses: codecov/codecov-action@v5
+      uses: codecov/codecov-action@v6
       with:
         token: ${{ secrets.CODECOV_TOKEN }}
         files: ./coverage.xml

.github/workflows/ci_docker.yml

@@ -30,7 +30,7 @@ jobs:
             apt-get update && apt-get install -y curl
 
         - name: Upload to codecov
-          uses: codecov/codecov-action@v5
+          uses: codecov/codecov-action@v6
           with:
             token: ${{ secrets.CODECOV_TOKEN }}
             files: ./coverage.xml