Update test-coverage.yaml

Author: chikuang

.github/workflows/test-coverage.yaml

@@ -45,6 +45,10 @@ jobs:
           plugin: noop
           disable_search: true
           token: ${{ secrets.CODECOV_TOKEN }}
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v4
+        env:
+          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
 
       - name: Show testthat output
         if: always()