Upgrade Codecov

Author: frankie567

.github/workflows/build.yml

@@ -28,7 +28,7 @@ jobs:
     - name: Test
       run: |
         hatch run test-cov-xml
-    - uses: codecov/codecov-action@v3
+    - uses: codecov/codecov-action@v4
       with:
         token: ${{ secrets.CODECOV_TOKEN }}
         fail_ci_if_error: true