Redis Linked Server Delete needs x-ms-long-running-operation: true

Developing a terraform resource type I had to put in a loop to watch for the resource to respond 404. Otherwise it fails to remove the redis cache servers because the link is still in a provisioningState "Deleting". Having the long running operations makes the code cleaner and more appropriate. See issue for downstream information.

x-ms-long-running-operation: true

https://github.com/Azure/azure-rest-api-specs/blob/50a94ccd66f49aed78efa24ceefd0d5c1186c8db/specification/redis/resource-manager/Microsoft.Cache/stable/2018-03-01/redis.json#L1207

https://github.com/Azure/azure-sdk-for-go/issues/12159

Open specification/redis/resource-manager/Microsoft.Cache/stable/2018-03-01/redis.json at the linked operation around line 1207 and read its DELETE definition first. Done means that operation declares x-ms-long-running-operation: true, matching the issue request; no test or run command is mentioned in the issue.

Written by the indexing model from the issue text.