1. Update the error message which currently says only the M10+ clusters can create the indexes

2. Attempt to create duplicate index throws incorrect error

 
OperationFailure: Duplicate Index, full error: {'ok': 0.0, 'errmsg': 'Duplicate Index', 'code': 68, 'codeName': 'IndexAlreadyExists', '$clusterTime': {'clusterTime': Timestamp(1729656959, 20), 'signature': {'hash': b'\x0bf\xea\xb4\xff|gd?f\xdfT\x1bHI\xa2cU\xed\x85', 'keyId': 7384804414130749441}}, 'operationTime': Timestamp(1729656959, 20)} The above exception was the direct cause of the following exception: OperationFailure Traceback (most recent call last)
/usr/local/lib/python3.10/dist-packages/langchain_mongodb/index.py in create_vector_search_index(collection, index_name, dimensions, path, similarity, filters, wait_until_complete, **kwargs) 87 ) 88 except OperationFailure as e: ---> 89 raise OperationFailure(_search_index_error_message()) from e 90 91 if wait_until_complete: OperationFailure: Search index operations are not currently available on shared clusters, such as MO. They require dedicated clusters >= M10. You may still perform vector search. You simply must set up indexes manually. Follow the instructions here: https://www.mongodb.com/docs/atlas/atlas-vector-search/vector-search-type/