Bump livekit ffi

[1egoman]

Warning

The livekit-ffi version is not updated in this yet.

Updates livekit-ffi to the latest version, which contains data streams v2.

In addition to the ffi package update itself, there's a bit more that has to be done here because the python sdk today has its own data streams implementation. I'm working on migrating this package to use the livekit-ffi provided data streams but in the meantime, if the livekit-ffi update was done today, then it would mean that the newly introduced client_protocol of 2 would be advertised, and the pre-existing node implementation would receive data stream v2 messages, not v1 (ie, single packet data streams, compression, etc could be sent to the existing python data streams code).

To address this, I've added a temporary options.data_stream.use_legacy_client_implementation flag which can be set to disable advertising the new client protocol. What this means in practice:

• Outgoing data streams will all be v1 (uses python data streams implementation)
• Incoming data streams will all be v1 (other participants see client_protocol of 1, so no inline content / compression)
• Outgoing RPCs will be potentially v1 or v2 (this within the rust code is powered by livekit-ffi's data streams implementation, just like it works today)
• Incoming RPCs will also potentially be v1 or v2 (for the same reason)

Once livekit-ffi data stream migration is done, I'll merge it and drop this flag both here and on the rust sdk end, and then everything will use data streams v2 everywhere.

I've tested this locally (all the data streams and rpc paths above) with success.

Todo

• Merge rust data streams v2 pull request: Data streams v2 rust-sdks#1192
• Do livekit-ffi release
• Bump version in here, then ci should pass
• Do final round of testing