KAFKA-15387: Deprecate Connect's redundant task configurations endpoint

[yashmayya]

• https://issues.apache.org/jira/browse/KAFKA-15387
• https://cwiki.apache.org/confluence/display/KAFKA/KIP-970%3A+Deprecate+and+remove+Connect%27s+redundant+task+configurations+endpoint
• This patch deprecates the GET /connectors/{connector}/tasks-config endpoint (by updating the documentation, adding a deprecated annotation to the OpenAPI spec, and adding a deprecation warning log).

Committer Checklist (excluded from commit message)

• Verify design and implementation
• Verify test coverage and CI build status
• Verify documentation (including upgrade notes)

[vamossagar12]

LGTM. Thanks for the fix Yash! I would have preferred a test which would have invoked the older end point and validates that the warning log line gets printed though. Other than that, seems fine.

[yashmayya]

Thanks Sagar!

a test which would have invoked the older end point and validates that the warning log line gets printed

Feels like a bit of overkill, but I guess it doesn't really hurt to add such a test so I've added one. There's currently no integration test class for Connect's REST API - most of the functionality is tested indirectly through other ITs and some of the more specialized ones have their own test classes (ConnectorRestartApiIntegrationTest, ConnectorTopicsIntegrationTest, OffsetsApiIntegrationTest etc.). It didn't seem worth it to introduce a new integration test class just for this small test so I've added it to ConnectWorkerIntegrationTest which is the most generic one.

[mimaison]

Thanks for the PR. LGTM

[yashmayya]

Test failures are unrelated, merging to trunk