We currently create the .async-search index if necessary before performing any action (index, update or delete). Truth is that this is needed only before storing the initial response. The other operations are either update or delete, which will anyways not find the document to update/delete even if the index gets created when missing. This also caused `testCancellation` failures as we were trying to delete the document twice from the .async-search index, once from `TransportDeleteAsyncSearchAction` and once as a consequence of the search task being completed. The latter may be called after the test is completed, but before the cluster is shut down and causing problems to the after test checks, for instance if it happens after all the indices have been cleaned up. It is totally fine to try to delete a response that is no longer found, but not quite so if such call will also trigger an index creation.
With this commit we remove all the calls to createIndexIfNecessary from the update/delete operation, and we leave one call only from storeInitialResponse which is where the index is expected to be created.
Closes#54180
93c39ad4e7