### 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)

} else {
			gui.subwindow_focused = nullptr;
		}
	}
	RenderingServer::get_singleton()->viewport_set_parent_viewport(p_window->viewport, p_window->parent ? p_window->parent->viewport : RID());
}
int Viewport::_sub_window_find(Window *p_window) const {
	for (int i = 0; i < gui.sub_windows.size(); i++) {
		if (gui.sub_windows[i].window == p_window) {
			return i;
		}
	}
	return -1;
}
void Viewport::_update_viewport_path() {
	if (viewport_textures.is_empty()) {
		return;
	}
	Node *scene_root = get_scene_file_path().is_empty() ? get_owner() : this;
	if (!scene_root && is_inside_tree()) {
		scene_root = get_tree()->get_edited_scene_root();
	}
	if (scene_root && (scene_root == this || scene_root->is_ancestor_of(this))) {
		NodePath path_in_scene = scene_root->get_path_to(this);
		for (ViewportTexture *E : viewport_textures) {
			E->path = path_in_scene;
		}
	}
}
void Viewport::_notification(int p_what) {