Fix incorrect unit test code sample in source generator docs (#54320)
Fix incorrect unit test code sample in source generator docs (#54320)


weltkante/roslyn,KevinRansom/roslyn,shyamnamboodiripad/roslyn,jasonmalinowski/roslyn,CyrusNajmabadi/roslyn,sharwell/roslyn,eriawan/roslyn,bartdesmet/roslyn,eriawan/roslyn,diryboy/roslyn,weltkante/roslyn,bartdesmet/roslyn,wvdd007/roslyn,mavasani/roslyn,shyamnamboodiripad/roslyn,KevinRansom/roslyn,diryboy/roslyn,mavasani/roslyn,wvdd007/roslyn,sharwell/roslyn,jasonmalinowski/roslyn,CyrusNajmabadi/roslyn,shyamnamboodiripad/roslyn,jasonmalinowski/roslyn,eriawan/roslyn,wvdd007/roslyn,dotnet/roslyn,KevinRansom/roslyn,sharwell/roslyn,weltkante/roslyn,dotnet/roslyn,CyrusNajmabadi/roslyn,dotnet/roslyn,bartdesmet/roslyn,diryboy/roslyn,mavasani/roslyn