### Godot version

v4.2.dev.custom_build [c3b0a92c3]

### System information

Debian Linux X11 Xfce

### Issue description

In the following scene tree it is not possible to write anything in `LineEditB`.
![image](https://github.com/godotengine/godot/assets/6299227/ce5f696a-d86a-402f-98f7-6a762f15543e)

I would expect, that it is possible to focus `LineEditB` with a mouse click and write into it.

Regression from #58334

### Steps to reproduce

1. Load and run MRP
2. Mouse Click into the left LineEditB
3. Type Keyboard => No letters appear in the LineEditB

Variant:

1. Load and run MRP
2. Mouse Click into the right LineEditA
3. Mouse Click into the left LineEditB
4. Type Keyboard => Letters appear in LineEditA instead of LineEditB


### Minimal reproduction project

[BugKeyInputRouting.zip](https://github.com/godotengine/godot/files/11994804/BugKeyInputRouting.zip)

#ifndef _3D_DISABLED
	if (!use_xr) {
#endif
		if (p_allocated) {
			RS::get_singleton()->viewport_set_size(viewport, size.width, size.height);
		} else {
			RS::get_singleton()->viewport_set_size(viewport, 0, 0);
		}
#ifndef _3D_DISABLED
	} 
#endif
	_update_global_transform();
	update_configuration_warnings();
	update_canvas_items();
	for (ViewportTexture *E : viewport_textures) {
		E->emit_changed();
	}
	emit_signal(SNAME("size_changed"));
	Rect2i limit = get_visible_rect();
	for (int i = 0; i < gui.sub_windows.size(); ++i) {
		Window *sw = gui.sub_windows[i].window;
		Rect2i rect = Rect2i(sw->position, sw->size);
		Rect2i new_rect = sw->fit_rect_in_parent(rect, limit);
		if (new_rect != rect) {
			sw->set_position(new_rect.position);
			sw->set_size(new_rect.size);
		}
	}
}
Size2i Viewport::_get_size() const {