### 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_MAIN_THREAD_GUARD;
	gui.canvas_sort_index = 0;
}
int Viewport::gui_get_canvas_sort_index() {
	ERR_MAIN_THREAD_GUARD_V(0);
	return gui.canvas_sort_index++;
}
void Viewport::gui_release_focus() {
	ERR_MAIN_THREAD_GUARD;
	if (gui.key_focus) {
		Control *f = gui.key_focus;
		gui.key_focus = nullptr;
		f->notification(Control::NOTIFICATION_FOCUS_EXIT, true);
		f->queue_redraw();
	}
}
Control *Viewport::gui_get_focus_owner() const {
	ERR_READ_THREAD_GUARD_V(nullptr);
	return gui.key_focus;
}
void Viewport::set_msaa_2d(MSAA p_msaa) {
	ERR_MAIN_THREAD_GUARD;
	ERR_FAIL_INDEX(p_msaa, MSAA_MAX);
	if (msaa_2d == p_msaa) {
		return;
	}
	msaa_2d = p_msaa;
	RS::get_singleton()->viewport_set_msaa_2d(viewport, RS::ViewportMSAA(p_msaa));
}
Viewport::MSAA Viewport::get_msaa_2d() const {