[FLINK-33437][connector] SinkV2 clear legacy state

[dyccode]

What is the purpose of the change

This pull request clears the legacy state of Sinkv2.

Brief change log

SinkV2 clears legacy states after initialization.

Verifying this change

Please make sure both new and modified tests in this PR follows the conventions defined in our code quality guide: https://flink.apache.org/contributing/code-style-and-quality-common.html#testing

(Please pick either of the following options)

This change is a trivial rework / code cleanup without any test coverage.

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: (yes)
• The S3 file system connector: (no)

Documentation

• Does this pull request introduce a new feature? (no)
• If yes, how is the feature documented? (not applicable / docs / JavaDocs / not documented)

[dyccode]

@flinkbot run azure

[flinkbot]

CI report:

• e9d1ae3 Azure: SUCCESS

Bot commands

The @flinkbot bot supports the following commands:

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

[dyccode]

@flinkbot run azure

[masteryhx]

LGTM.
I just thinked whether it could be tested easily.
Since it's related to the migration of Kafka Sink, Do you have any other comments?
@PatrickRen

[dyccode]

@masteryhx Thanks for the review.What I need to do to merge this pr? Looking forward to your reply.

[masteryhx]

Sorry for the late reply.
The PR is fine. I will merge it.

[masteryhx]

merged efbd8c4 into master