gpu: do not show window until initialization complete

some new versions of gnome has bug, after long delay it thinks that window still freezed even if it responses

rpcsx/gpu/Device.cpp

@@ -92,6 +92,8 @@ static vk::Context createVkContext(Device *device) {
   createWindow();
 #endif
 
+  glfwHideWindow(device->window);
+
   const char **glfwExtensions;
   uint32_t glfwExtensionCount = 0;
   glfwExtensions = glfwGetRequiredInstanceExtensions(&glfwExtensionCount);
@@ -345,6 +347,8 @@ void Device::start() {
   uint32_t gpIndex = -1;
   GLFWgamepadstate gpState;
 
+  glfwShowWindow(window);
+
   while (true) {
     glfwPollEvents();