Undo wxGLCanvas::SwapBuffers() Wayland frame sync.

This reverts the frame synchronization logic that was recently added
with the purpose of avoiding performance issues due to `eglSwapBuffers`
blocking when the canvas is hidden or occluded.

This logic should be unnecessary after `eglSwapInterval(display, 0)`
is called, since `eglSwapBuffers` should never block anymore.
Furthermore, as it stands now, it causes the canvas to continuously
repaint itself at the refresh rate of the display, which is wasteful
for applications which do not need to continuously refresh.

See wxWidgets#24012, wxWidgets#24017.

(cherry picked from commit abfdd18)

Author: joanbm

src/unix/glegl.cpp

@@ -843,21 +843,13 @@ bool wxGLCanvasEGL::SwapBuffers()
 #ifdef GDK_WINDOWING_WAYLAND
     if (wxGTKImpl::IsWayland(window))
     {
-        // Under Wayland, we must not draw before we're actually ready to, as
-        // this would be inefficient at best and could result in a deadlock at
-        // worst if we're called before the window is realized.
+        // Under Wayland, we must not draw before the window has been realized,
+        // as this could result in a deadlock inside eglSwapBuffers()
         if ( !m_readyToDraw )
         {
             wxLogTrace(TRACE_EGL, "Window %p is not not ready to draw yet", this);
             return false;
         }
-
-        // Ensure that we redraw again when the frame becomes ready.
-        m_readyToDraw = false;
-        wl_surface* surface = gdk_wayland_window_get_wl_surface(window);
-        m_wlFrameCallbackHandler = wl_surface_frame(surface);
-        wl_callback_add_listener(m_wlFrameCallbackHandler,
-                                 &wl_frame_listener, this);
     }
 #endif // GDK_WINDOWING_WAYLAND