add maven Xmx to 5g

.github/workflows/ci_ut.yml

@@ -62,7 +62,7 @@ jobs:
           git fetch origin
       - name: Compile
         run: |
-          export MAVEN_OPTS='-Dmaven.repo.local=.m2/repository -XX:+TieredCompilation -XX:TieredStopAtLevel=1 -XX:+CMSClassUnloadingEnabled -XX:+UseConcMarkSweepGC -XX:-UseGCOverheadLimit -Xmx3g'
+          export MAVEN_OPTS='-Dmaven.repo.local=.m2/repository -XX:+TieredCompilation -XX:TieredStopAtLevel=1 -XX:+CMSClassUnloadingEnabled -XX:+UseConcMarkSweepGC -XX:-UseGCOverheadLimit -Xmx5g'
           mvn test -B -Dmaven.test.skip=false
       - name: Upload coverage report to codecov
         run: |