Comms Handshake doesn't handle blosc effectively

[mrocklin]

I ran into an issue with @therriault where remote workers had Blosc, but the Client didn't. This resulted in un-decompressible data being shipped to the client.

I was surprised that this occured because he was after 2.23 where the handshake was implemented. My guess is that serialization functions are using blosc outside of the normal compression channels and don't have the handshake information.

[mrocklin]

Here is a notebook from @therriault . It includes another failure with Joblib if anyone wants to try that out as well: https://gist.github.com/mrocklin/0a332b477dabc1a55fbbdaa2d08a5333

[jakirkham]

Closing as Blosc was dropped ( #6027 )