subscription_thread_dispatcher: guard against duplicate room events #270

Job	Run time
Detect Changes	4s
Link Check / Link Check	7s
License Check / License Check	5s
Generate Docs / Generate and verify docs	34s
Tests / Code Coverage	18m 17s
C++ Checks / clang-format	19s
Builds / Build (macos-arm64)	4m 11s
Builds / Build (windows-x64)	10m 49s
Builds / Build (macos-x64)	19m 59s
Tests / Test (macos-arm64)	8m 1s
C++ Checks / clang-tidy	11m 9s
Tests / Test (linux-x64)	10m 15s
Tests / Test (linux-arm64)	9m 19s
Tests / Test (windows-x64)	14m 57s
Tests / Test (macos-x64)	19m 42s
Builds / Build (linux-x64)	9m 11s
Builds / Build (linux-arm64)	7m 48s
Rust Release Check	-1s
Docker Images	-1s
CI	3s
	2h 24m 48s

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