Defer build index that is not built is not being deleted when the bucket is deleted

Defer build index that is not built is not being deleted when the bucket is deleted. Built index works, it will get removed when the bucket is gone.

Reproduce case:
1. Create a bucket named `user`
2. Create index with defer build true and not executing BUILD INDEX: [CREATE INDEX index_userId ON `user`(userId) WHERE meta().id LIKE 'user/%' WITH

;]
3. Delete bucket `user`
4. Index UI still have the index being displayed
5. Execute query of [SELECT * FROM system:indexes;] returns nothing - no index.
6. Repeat step 1
7. Repeat step 2 [Error code: 4300, message: "The index index_userId already exists."]

If step 5 is true, step 7 should be succeed.