remove push_cnab test in CI

push_cnab test need to pull docker image from dockerhub, which meet rate limitation sometime

Signed-off-by: Ziming Zhang <zziming@vmware.com>

.github/scripts/apidb_test.sh

@@ -13,7 +13,7 @@ sed -i '15i\    ${dfout}=  Run  df -h\n    Log To Console  ${dfout}' harbor/test
 sed -i 's/timeout=30/timeout=300/g' harbor/tests/apitests/python/library/docker_api.py
 
 
-EXCLUDES="--exclude metrics --exclude singularity --exclude proxy_cache"
+EXCLUDES="--exclude metrics --exclude singularity --exclude proxy_cache --exclude push_cnab"
 ROBOT_FILES="/drone/tests/robot-cases/Group1-Nightly/Setup.robot /drone/tests/robot-cases/Group0-BAT/API_DB.robot"
 CMD="robot -v DOCKER_USER:$DOCKER_USER -v DOCKER_PWD:$DOCKER_PWD -v ip:$CORE_HOST -v ip1: -v HARBOR_PASSWORD:Harbor12345 -v http_get_ca:true $EXCLUDES $ROBOT_FILES"