docs:support Codecov.

Signed-off-by: Haotian Zhang <[email protected]>

Author: SkyeBeFreeman

.github/workflows/testing.yml

@@ -62,4 +62,8 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-maven-
       - name: Test with Maven
-        run: mvn -B test --file pom.xml
+        run: mvn clean test -B -U --file pom.xml
+      - name: Upload coverage reports to Codecov
+        uses: codecov/codecov-action@v4
+        env:
+          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}