docs:add codecov token.

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

Author: SkyeBeFreeman

.github/workflows/testing.yml

@@ -38,3 +38,5 @@ jobs:
         run: mvn clean test -B -U -Psonatype --file pom.xml
       - name: Upload coverage reports to Codecov
         uses: codecov/codecov-action@v4
+        env:
+          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}