Fix crash at exit

src/video_core/debug_utils/debug_utils.h

@@ -55,8 +55,10 @@ public:
         virtual ~BreakPointObserver() {
             auto context = context_weak.lock();
             if (context) {
+                {
                     std::unique_lock<std::mutex> lock(context->breakpoint_mutex);
                     context->breakpoint_observers.remove(this);
+                }
 
                 // If we are the last observer to be destroyed, tell the debugger context that
                 // it is free to continue. In particular, this is required for a proper yuzu