The docarray [integration
PR](#4483) introduced a
pinned dependency to protobuf.

As library developers, we should avoid pinned dependencies as this
quickly leads to incompatibilities with application code. Much less
with a heavily used library like protobuf.

As we see in the [docarray
integration](https://github.com/hwchase17/langchain/pull/4483/files#diff-50c86b7ed8ac2cf95bd48334961bf0530cdc77b5a56f852c5c61b89d735fd711R81-R83),
the transitive dependencies of docarray were also listed as langchain
dependencies. This is unnecessary as the docarray project has an
[extras
install](https://github.com/docarray/docarray/blob/a01a05542d17264b8a164bec783633658deeedb8/pyproject.toml#L70)
that lists these.

This PR reverts the explicit hnswlib and protobuf dependencies and
adds the hnswlib extras install for docarray (which installs hnswlib
and protobuf). Because version 0.32.0
of the docarray hnswlib extras added protobuf, we bump the docarray
dependency from `^0.31.0` to `^0.32.0`.

Also fix merge conflicts in pyproject.toml and poetry.lock.

An extra was previously introduced for "hnswlib" which only installed
"docarray". While "hnswlib" is a dependency of docarray, docarray is a
separate integration, so this is misleading to users.

There was also a separate extras for "in_memory_store". This is again
misleading since there are various in memory stores in the system that
are very specific.