Remove smoke load test for Java and Python SDK

As discussed in PR: [https://github.com/apache/beam/pull/11135#discussion_r392852028](https://github.com/apache/beam/pull/11135#discussion_r392852028) 

No one seems to use them and regular load test will fail too whenever something is wrong. There's plenty of load tests now and they are smaller than they used to be at the time of creating the smoke tests. If something is wrong there will be quite quick feedback from them. All that makes the smoke test redundant imo. 

Imported from Jira [BEAM-9559](https://issues.apache.org/jira/browse/BEAM-9559). Original Jira may contain additional context.
Reported by: ŁukaszG.

Start by reviewing the linked PR discussion and locating the Java and Python smoke load tests referenced there. Confirm the regular load tests that replace their coverage, then remove the redundant smoke tests; done means the regular load tests remain available without the smoke-test targets.

Written by the indexing model from the issue text.