[WASI] fix event loop init

[pavelsavara]

src\libraries\System.Private.CoreLib\src\System\Threading\ThreadPoolWorkQueue.cs

#if !TARGET_WASI
            // TODO fixme
            Debug.Assert(workQueue._separated.queueProcessingStage == (int)QueueProcessingStage.Scheduled);
#endif

[dotnet-policy-service]

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