codecov: enable codecov in our repo

this commit add the configuration for codecov,
to be able to see the coverage of vitest in codecov website.

.github/workflows/dev-checks.yml

@@ -28,4 +28,10 @@ jobs:
     - name: Run lint check
       run: npm run lint
     - name: Run unit tests
-      run: npm run test
+      run: npm run test:coverage
+    - name: Upload coverage to Codecov
+      uses: codecov/codecov-action@v4
+      with:
+        token: ${{ secrets.CODECOV_TOKEN }}
+        files: ./coverage/junit.xml
+        verbose: true