wasm: Fix UB in QEventDispatcher

Calling std::mutex::try_lock() when the mutex is already owned by
the thread casuses undefined behavior.

Change-Id: I024ced271cad8a034bebf80b48e31e7e7461c560
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>

src/corelib/kernel/qeventdispatcher_wasm.cpp

@@ -271,7 +271,6 @@ bool QEventDispatcherWasm::isValidEventDispatcherPointer(QEventDispatcherWasm *e
     if (eventDispatcher == g_mainThreadEventDispatcher)
         return true;
 #if QT_CONFIG(thread)
-    Q_ASSERT(!g_staticDataMutex.try_lock()); // caller must lock mutex
     if (g_secondaryThreadEventDispatchers.contains(eventDispatcher))
         return true;
 #endif