### 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)

ERR_READ_THREAD_GUARD_V(Ref<World2D>());
	if (world_2d.is_valid()) {
		return world_2d;
	} else if (parent) {
		return parent->find_world_2d();
	} else {
		return Ref<World2D>();
	}
}
void Viewport::_propagate_viewport_notification(Node *p_node, int p_what) {
	p_node->notification(p_what);
	for (int i = 0; i < p_node->get_child_count(); i++) {
		Node *c = p_node->get_child(i);
		if (Object::cast_to<Viewport>(c)) {
			continue;
		}
		_propagate_viewport_notification(c, p_what);
	}
}
Ref<World2D> Viewport::get_world_2d() const {
	ERR_READ_THREAD_GUARD_V(Ref<World2D>());
	return world_2d;
}
Camera2D *Viewport::get_camera_2d() const {