Update to fix InvokeAsync usage

[BertanAygun]

InvokeAsync extension method internally handles the event handler being null, per recommendation patterns like "await StartAsync?.InvokeAsync" should be awaited since it will cause NullReferenceException in case StartAsync is null. Removing "?" and letting InvokeAsync handle it does the expected action which is a no-op

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[PRMerger17]

@BertanAygun : Thanks for your contribution! The author, @gregvanl, has been notified to review your proposed change.

[gregvanl]

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