### Godot version

4.0.3-stable

### System information

Windows 10

### Issue description

In some projects ViewportTexture remains pink and doesn't render viewport content after upgrading from 4.0.2-stable to 4.0.3-stable. If a pair of files viewport.h/viewport.cpp are downgraded back to what they were in 4.0.2-stable, problem goes away.

This is how it looks in 4.0.3-stable:
![4 0 3_stable_viewport_4 0 3](https://github.com/godotengine/godot/assets/1449921/44c191a9-4b67-4b02-90b6-4ab615f62a73)

And this is how it looks if viewport.h/viewport.cpp are downgraded back to what they were in 4.0.2-stable.
![4 0 3_stable_viewport_4 0 2](https://github.com/godotengine/godot/assets/1449921/f5abc605-f129-4222-9c0e-e9a07621dd9d)



### Steps to reproduce

Unfortunately, I cannot come up wit a simple demo project reproducing the problem. It exists in some projects and doesn't exist in others.


### Minimal reproduction project

Cannot produce a simple project reproducing the problem. In simple projects it works fine.
if (gui.drag_data.get_type() != Variant::NIL) {
								gui.mouse_focus = nullptr;
								gui.forced_mouse_focus = false;
								gui.mouse_focus_mask.clear();
								break;
							} else {
								Control *drag_preview = _gui_get_drag_preview();
								if (drag_preview) {
									ERR_PRINT("Don't set a drag preview and return null data. Preview was deleted and drag request ignored.");
									memdelete(drag_preview);
									gui.drag_preview_id = ObjectID();
								}
								gui.dragging = false;
							}
							if (control->data.mouse_filter == Control::MOUSE_FILTER_STOP) {
								break;
							}
						}
						if (ci->is_set_as_top_level()) {
							break;
						}
						ci = ci->get_parent_item();
					}
				}
				gui.drag_attempted = true;
				if (gui.dragging) {
					_propagate_viewport_notification(this, NOTIFICATION_DRAG_BEGIN);
				}
			}
		}