test: Bump codecov to v4

And since codecov@v4 no longer supports tokenless uploading, use the org
token to do so.

Author: arbrandes

.github/workflows/ci.yml

@@ -30,4 +30,6 @@ jobs:
     - name: i18n_extract
       run: npm run i18n_extract
     - name: Coverage
-      uses: codecov/codecov-action@v3
+      uses: codecov/codecov-action@v4
+      env:
+        CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}