FullscreenUI: Remove content start sound effect

This ended up being way more annoying than I thought it would be.

src/core/fullscreenui.cpp

@@ -127,7 +127,6 @@ static constexpr std::string_view ABOUT_DIALOG_NAME = "##about_duckstation";
 const char* SFX_NAV_ACTIVATE = "sounds/nav_activate.wav";
 const char* SFX_NAV_BACK = "sounds/nav_back.wav";
 const char* SFX_NAV_MOVE = "sounds/nav_move.wav";
-const char* SFX_CONTENT_START = "sounds/content_start.wav";
 
 //////////////////////////////////////////////////////////////////////////
 // State
@@ -618,8 +617,6 @@ void FullscreenUI::DoStartPath(std::string path, std::string state, std::optiona
   if (GPUThread::HasGPUBackend())
     return;
 
-  EnqueueSoundEffect(SFX_CONTENT_START);
-
   // Stop running idle to prevent game list from being redrawn until we know if startup succeeded.
   GPUThread::SetRunIdleReason(GPUThread::RunIdleReason::FullscreenUIActive, false);
 

src/core/fullscreenui.h

@@ -101,7 +101,6 @@ private:
 extern const char* SFX_NAV_ACTIVATE;
 extern const char* SFX_NAV_BACK;
 extern const char* SFX_NAV_MOVE;
-extern const char* SFX_CONTENT_START;
 
 } // namespace FullscreenUI