Remove the default machine types (apache#33191)

From apache#30507 (comment), try to use the default machine types for Flink with more memory.

Author: liferoad

.test-infra/dataproc/flink_cluster.sh

@@ -131,10 +131,8 @@ function create_cluster() {
 
   # Docker init action restarts yarn so we need to start yarn session after this restart happens.
   # This is why flink init action is invoked last.
-  # TODO(11/11/2022) remove --worker-machine-type and --master-machine-type once N2 CPUs quota relaxed
-  # Dataproc 2.1 uses n2-standard-2 by default but there is N2 CPUs=24 quota limit
   gcloud dataproc clusters create $CLUSTER_NAME --region=$GCLOUD_REGION --num-workers=$FLINK_NUM_WORKERS --public-ip-address \
-  --master-machine-type=n1-standard-2 --worker-machine-type=n1-standard-2 --metadata "${metadata}", \
+  --metadata "${metadata}", \
   --image-version=$image_version --zone=$GCLOUD_ZONE  --optional-components=FLINK,DOCKER  --quiet
 }