* Replaces Python implementation of Remote SDK with Rust one.
* Drops dependency on `attrs` and `cachetools`. Makes `requests` an
optional dependency used only for embeddings feature.
* Adds dependency on `nest-asyncio`. This was required to get hybrid
search working.
* Deprecate `request_thread_pool` parameter. We now use the tokio
threadpool.
* Stop caching the `schema` on a remote table. Schema is mutable and
there's no mechanism in place to invalidate the cache.
* Removed the client-side resolution of the vector column. We should
already be resolving this server-side.
This changes `lancedb` from a "pure python" setuptools project to a
maturin project and adds a rust lancedb dependency.
The async python client is extremely minimal (only `connect` and
`Connection.table_names` are supported). The purpose of this PR is to
get the infrastructure in place for building out the rest of the async
client.
Although this is not technically a breaking change (no APIs are
changing) it is still a considerable change in the way the wheels are
built because they now include the native shared library.
