rtc-v0.22.0

What's Changed

• remove AudioFrame.remix_and_resample by @theomonnom in https://github.com/livekit/python-sdks/pull/385
• remove ChatManager by @theomonnom in https://github.com/livekit/python-sdks/pull/387
• serialize VideoBufferType using human-readable str by @theomonnom in https://github.com/livekit/python-sdks/pull/392
• better track types by @theomonnom in https://github.com/livekit/python-sdks/pull/393
• update CI to use protobuf 4.x by @davidzhao in https://github.com/livekit/python-sdks/pull/396
• version bump 0.22 by @davidzhao in https://github.com/livekit/python-sdks/pull/397

Full Changelog: https://github.com/livekit/python-sdks/compare/rtc-v0.21.3...rtc-v0.22.0