github/workflows: Bump codecov/codecov-action from 4 to 5.

Bumps [codecov/codecov-action](https://github.com/codecov/codecov-action) from 4 to 5.
- [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...v5)

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

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

Author: dependabot[bot]

.github/workflows/ports_unix.yml

@@ -88,7 +88,7 @@ jobs:
         (cd ports/unix && gcov -o build-coverage/py ../../py/*.c || true)
         (cd ports/unix && gcov -o build-coverage/extmod ../../extmod/*.c || true)
     - name: Upload coverage to Codecov
-      uses: codecov/codecov-action@v4
+      uses: codecov/codecov-action@v5
       with:
         fail_ci_if_error: true
         verbose: true