fix: Remove sync parameter from create_endpoint_sample (#695)

Remove unused `sync` parameter from `create_endpoint_sample`

Googlers see 195511018

Author: aribray

samples/model-builder/create_endpoint_sample.py

@@ -17,7 +17,7 @@
 
 #  [START aiplatform_sdk_create_endpoint_sample]
 def create_endpoint_sample(
-    project: str, display_name: str, location: str, sync: bool = True,
+    project: str, display_name: str, location: str,
 ):
     aiplatform.init(project=project, location=location)