chore(ci): upgrade to codecov v4

Author: thomasrockhu-codecov

.github/workflows/ci.yml

@@ -15,4 +15,4 @@ jobs:
       - name: Run tests and collect coverage
         run: npm run test
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v3
+        uses: codecov/codecov-action@v4