Data blob support ships; egress v2 API added

Added

• Add Prometheus metrics for join latency and peer connection state (#4574, #4616)
• Preserve original expiry when refreshing token (#4580)
• Add grants expiry to Auth context (#4581)
• Add ability to run pprof on dedicated HTTP server (#4584)
• Add API to get latest node stats (#4589)
• Enforce subscription permission to data track (#4588)
• egress v2 api (#4592)
• agent: thread attributes map from dispatch to job (#4598)
• Log subscription limit breaches (#4603)
• Acquire requested video layer directly at HIGH quality by default (#4595)
• Report participant capabilities in ParticipantInfo (#4606)
• Add option to force drain rtcService/agentService connections (#4618)
• Add support for data blob (a. k. a. async participant attributes) (#4619)

Changed

• Update dependencies: pion/sctp, DTLS v3.1.4, protocol (#4587, #4601, #4623)
• rtc: add RestartSessionTimer to re-anchor participant session duration (#4566)
• Record more RTC cancellation points (#4600)
• Cap all metadata at 512 KiB; enforce on join, agent dispatch, and embedded agents (#4602)
• Tighten up publish latency stat (#4615)
• Echo offered audio payload types in single-PC subscriber answer (#4614)

Fixed

• Fix skipped packets accounting (#4604)
• Do not log due to negative getting interpreted as large unsigned positive (#4605)
• Do not call nil callback (#4607)