remove dispatcher table in meta store in later release

[wenym1]

Is your feature request related to a problem? Please describe.

After #20541, we will not use dispatcher meta store table anymore. Nevertheless, we will instead use a fragment_relation table instead, and the backfill of this table depends on the original rows in dispatcher table. Therefore, we may not remove the dispatcher table immediately. We shall keep the dispatcher in the coming release 2.3.0, and add a migration script to remove the dispatcher table in the later release.

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