chore(deps): 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] <[email protected]>

Author: dependabot[bot]

.github/workflows/test-coverage.yaml

@@ -38,7 +38,7 @@ jobs:
           covr::to_cobertura(cov)
         shell: Rscript {0}
 
-      - uses: codecov/codecov-action@v5
+      - uses: codecov/codecov-action@v6
         with:
           # Fail if error if not on PR, or if on PR and token is given
           fail_ci_if_error: ${{ github.event_name != 'pull_request' || secrets.CODECOV_TOKEN }}
@@ -87,7 +87,7 @@ jobs:
         run: cargo llvm-cov --workspace --all-features --lcov  --ignore-filename-regex "src/lib.rs" --output-path lcov.info
 
       - name: Upload Rust coverage to Codecov (flag=rust)
-        uses: codecov/codecov-action@v5
+        uses: codecov/codecov-action@v6
         with:
           files: src/rust/lcov.info
           flags: rust