* feat(serverless): expose CollectionsService response time
Sync the serverless collections proto with the public-api `time` field and
surface it on create/delete/get/list results (sync and async clients).
* feat(serverless): drop objects_deleted from delete result
Match public-api DeleteCollectionResponse after removing the storage
object count from the tenant-facing delete reply.
* chore(serverless): sync DeleteCollectionResponse.time to field 2