Avoid retrying renderer init if we know the error was not transient

app/streaming/video/ffmpeg-renderers/vt_metal.mm

@@ -699,6 +699,7 @@ public:
 
         id<MTLDevice> device = getMetalDevice();
         if (!device) {
+            m_InitFailureReason = InitFailureReason::NoSoftwareSupport;
             return false;
         }
 
@@ -719,6 +720,7 @@ public:
             SDL_LogWarn(SDL_LOG_CATEGORY_APPLICATION,
                         "av_hwdevice_ctx_create() failed for VT decoder: %d",
                         err);
+            m_InitFailureReason = InitFailureReason::NoSoftwareSupport;
             return false;
         }