v38.1.0-rc.0

✨ Features

• Remove custom org.matrix.msc4075.rtc.notification.parent relation type (#4979). Contributed by @toger5.
• MatrixRTC: Add RTC decline event (#4978). Contributed by @toger5.
• Make a MatrixRTCSession emit once the RTCNotification is sent (#4976). Contributed by @toger5.
• Use hydra semantics for unknown room versions (#4957). Contributed by @dbkr.
• Expose the StatusChanged event through the RTCSession (#4974). Contributed by @toger5.
• Add probablyLeft event to the MatrixRTCSession (#4962). Contributed by @toger5.

🐛 Bug Fixes

• Fix m.topic format (#4984). Contributed by @tulir.
• Fix stable-suffixed MSC4133 support (#4983). Contributed by @dbkr.
• Fix thread edit aggregation race condition (#4980). Contributed by @basnijholt.