Fix mistake in BotR Threading section (#104183)

Fixes #79248

Author: jkotas

docs/design/coreclr/botr/threading.md

@@ -142,7 +142,7 @@ If there is room on the object header, Monitor stores the managed thread ID of t
 
 If the lock cannot be acquired in this manner after some number of spins, or the object header is already being used for other purposes, a sync block must be created for the object. This has additional data, including an event that can be used to block the current thread, allowing us to stop spinning and efficiently wait for the lock to be released.
 
-An object that is used as a condition variable (via Monitor.Wait and Monitor.Pulse) must always be inflated, as there is not enough room in the sync block to hold the required state.
+An object that is used as a condition variable (via Monitor.Wait and Monitor.Pulse) must always be inflated, as there is not enough room in the object header to hold the required state.
 
 Synchronization: Native
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