changefeedccl: don't double-wait on non-local node drain

NOTE: none of this is turned on when the changefeed drain watcher is disabled, which it currently is.

Currently when a CA node drains, the changefeed coordinator wait for two backoff times instead of one: https://github.com/massimo-ua/cockroach/blob/1d9d751addbe2bc1e01c973c60bc35bbd96e6165/pkg/ccl/changefeedccl/changefeed_stmt.go#L1564 .
There's no good reason for this and we shouldn't do it.

For reference, ldr & pcr do not handle this at all.

Jira issue: CRDB-52418