build: Update codecov and use token (#398)

Update codecov to the latest version and start using the org-wide token for uploads.

See https://github.com/openedx/wg-frontend/issues/179

.github/workflows/ci.yml

@@ -43,7 +43,10 @@ jobs:
       run: npm run build
 
     - name: Run Coverage
-      uses: codecov/codecov-action@v2
+      uses: codecov/codecov-action@v4
+      with:
+        token: ${{ secrets.CODECOV_TOKEN }}
+        fail_ci_if_error: true
 
     - name: Send failure notification
       if: ${{ failure() }}