### 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;
	ERR_FAIL_NULL(p_viewport);
	ERR_FAIL_NULL(p_control);
	if (gui.mouse_focus) {
		p_viewport->gui.mouse_focus = p_control;
		p_viewport->gui.mouse_focus_mask = gui.mouse_focus_mask;
		p_viewport->gui.key_focus = p_control;
		p_viewport->gui.forced_mouse_focus = true;
		gui.mouse_focus = nullptr;
		gui.forced_mouse_focus = false;
		gui.mouse_focus_mask.clear();
	}
}
void Viewport::set_sdf_oversize(SDFOversize p_sdf_oversize) {
	ERR_MAIN_THREAD_GUARD;
	ERR_FAIL_INDEX(p_sdf_oversize, SDF_OVERSIZE_MAX);
	sdf_oversize = p_sdf_oversize;
	RS::get_singleton()->viewport_set_sdf_oversize_and_scale(viewport, RS::ViewportSDFOversize(sdf_oversize), RS::ViewportSDFScale(sdf_scale));
}
Viewport::SDFOversize Viewport::get_sdf_oversize() const {
	ERR_READ_THREAD_GUARD_V(SDF_OVERSIZE_100_PERCENT);
	return sdf_oversize;
}
void Viewport::set_sdf_scale(SDFScale p_sdf_scale) {
	ERR_MAIN_THREAD_GUARD;
	ERR_FAIL_INDEX(p_sdf_scale, SDF_SCALE_MAX);
	sdf_scale = p_sdf_scale;
	RS::get_singleton()->viewport_set_sdf_oversize_and_scale(viewport, RS::ViewportSDFOversize(sdf_oversize), RS::ViewportSDFScale(sdf_scale));
}
Viewport::SDFScale Viewport::get_sdf_scale() const {