### 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_FAIL_COND(p_event.is_null());
	Ref<InputEventMouseButton> mb = p_event;
	if (mb.is_valid()) {
		gui.key_event_accepted = false;
		Point2 mpos = mb->get_position();
		if (mb->is_pressed()) {
			if (!gui.mouse_focus_mask.is_empty()) {
				
				gui.mouse_focus_mask.set_flag(mouse_button_to_mask(mb->get_button_index()));
			} else {
				gui.mouse_focus = gui_find_control(mpos);
				gui.last_mouse_focus = gui.mouse_focus;
				if (!gui.mouse_focus) {
					return;
				}