NanoMQ 0.21.6

What's Changed

• • FIX [QUIC] fix #866 by @JaylinYu in #867
• Expose rwlock to the upper layer. by @wanghaEMQ in #868
• Fix multiple bugs in new QUIC trasnport by @JaylinYu in #869
• Sync mqttv311 protocol layer changes to mqttv5 protocol layer,. by @wanghaEMQ in #870
• Fix multiple minor issues in QUIC protocol layer by @JaylinYu in #871
• Fix nanomq/nanomq#1686 by @JaylinYu in #872
• • FIX [msquic_dial] fix #873 by @JaylinYu in #874

Full Changelog: 0.21.5...0.21.6