### 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)

int index = _sub_window_find(p_window);
	ERR_FAIL_COND(index == -1);
	ERR_FAIL_NULL(RenderingServer::get_singleton());
	RS::get_singleton()->free(gui.sub_windows[index].canvas_item);
	gui.sub_windows.remove_at(index);
	if (gui.sub_windows.size() == 0) {
		RS::get_singleton()->free(subwindow_canvas);
		subwindow_canvas = RID();
	}
	if (gui.currently_dragged_subwindow == p_window) {
		gui.subwindow_drag = SUB_WINDOW_DRAG_DISABLED;
		gui.currently_dragged_subwindow = nullptr;
	}
	if (gui.subwindow_focused == p_window) {
		Window *new_focused_window;
		Window *parent_visible = p_window->get_parent_visible_window();
		gui.subwindow_focused->_event_callback(DisplayServer::WINDOW_EVENT_FOCUS_OUT);
		if (parent_visible) {
			new_focused_window = parent_visible;
		} else {
			new_focused_window = Object::cast_to<Window>(this);
		}
		if (new_focused_window) {
			int new_focused_index = _sub_window_find(new_focused_window);
			if (new_focused_index != -1) {
				gui.subwindow_focused = new_focused_window;
			} else {
				gui.subwindow_focused = nullptr;
			}
			new_focused_window->_event_callback(DisplayServer::WINDOW_EVENT_FOCUS_IN);