Wayland: Fix duplicate window content scale events

The window content scale event was emitted every time the window content
area was resized, even if its scale had not changed.

(cherry picked from commit 0b76e3a6f1)

src/wl_window.c

@@ -356,7 +356,6 @@ static void resizeWindow(_GLFWwindow* window)
     if (!window->wl.transparent)
         setOpaqueRegion(window);
     _glfwInputFramebufferSize(window, scaledWidth, scaledHeight);
-    _glfwInputWindowContentScale(window, scale, scale);
 
     if (!window->wl.decorations.top.surface)
         return;
@@ -403,6 +402,7 @@ static void checkScaleChange(_GLFWwindow* window)
     {
         window->wl.scale = maxScale;
         wl_surface_set_buffer_scale(window->wl.surface, maxScale);
+        _glfwInputWindowContentScale(window, maxScale, maxScale);
         resizeWindow(window);
     }
 }