token is apparently needed for main and other "unprefixed" branches

- c.f. https://docs.codecov.com/docs/codecov-tokens#tokenless-on-unprotected-branches

Author: agilgur5

.github/workflows/ci.yml

@@ -33,3 +33,5 @@ jobs:
       run: npm run test:coverage
     - name: Upload coverage report to Codecov
       uses: codecov/codecov-action@v5
+      with:
+        token: ${{ secrets.CODECOV_TOKEN }}