increase the open file descriptors limit

Author: chandra-siri

cloudbuild/run_zonal_tests.sh

@@ -23,4 +23,5 @@ echo '--- Setting up environment variables on VM ---'
 export ZONAL_BUCKET=${_ZONAL_BUCKET}
 export RUN_ZONAL_SYSTEM_TESTS=True
 echo '--- Running Zonal tests on VM ---'
+ulimit -n 1048576
 pytest -vv -s --log-format='%(asctime)s %(levelname)s %(message)s' --log-date-format='%H:%M:%S' tests/system/test_zonal.py