[FLINK-36175][python] Remove `register_table_source` and `register_table_sink` in python module

[xuyangzhong]

What is the purpose of the change

Remove apis about register_table_source and register_table_sink in python module

Brief change log

• Remove register_table_source and register_table_sink in python module
• Update document in python

Verifying this change

This change is already covered by existing tests.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): no
• The public API, i.e., is any changed class annotated with @Public(Evolving): no
• The serializers: no
• The runtime per-record code paths (performance sensitive): no
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn, ZooKeeper: no
• The S3 file system connector: no

Documentation

• Does this pull request introduce a new feature? no
• If yes, how is the feature documented?

[flinkbot]

CI report:

• e96f1bf8234dbd77a688da6c7d9f141aa6149765 Azure: FAILURE

Bot commands

The @flinkbot bot supports the following commands:

• @flinkbot run azure re-run the last Azure build

[xuyangzhong]

The failed test is traced by https://issues.apache.org/jira/browse/FLINK-36293