Register the Matrix room-message, reaction, and invite handlers with
mautrix's wait_sync=True. mautrix's handle_sync() only returns the tasks
for handlers registered as sync-awaited; non-waited handlers are
fire-and-forget via background_task.create() and are NOT returned. Since
_dispatch_sync() awaits only the returned tasks (await asyncio.gather),
the inbound handlers previously had no completion point, so Tuwunel/
mautrix homeservers connected and completed initial sync but dispatched
zero inbound messages.
Fixes#46142.
Co-authored-by: Zeheng Huang <153708448+hunjaiboy@users.noreply.github.com>
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