### Godot version

4.0.2.stable.official [7a0977ce2]

### System information

Windows 10

### Issue description

LineEdit node with enabled "expand_to_text_length" option and "minimum_character_width = 0" and cleared margins in style overrides still has some empty space inside
![node](https://github.com/godotengine/godot/assets/23380802/86c79678-8422-4a98-8406-602edd7dc48b)
![node settings](https://github.com/godotengine/godot/assets/23380802/11d04d71-bbf1-4c16-8155-fe39b5bbd66b)
![style overrides](https://github.com/godotengine/godot/assets/23380802/6b3c3925-b4bd-455b-aac1-ddeb54a4d796)


### Steps to reproduce

1. Add LineEdit node
2. Set expand_to_text_length = true
3. Set minimum_character_width in theme overrides = 0
4. Set normal to StyleBoxEmpty


### Minimal reproduction project

[LineEdit can't be zero sized.zip](https://github.com/godotengine/godot/files/11566017/LineEdit.can.t.be.zero.sized.zip)

if (right_icon == p_icon) {
		return;
	}
	right_icon = p_icon;
	_fit_to_width();
	update_minimum_size();
	queue_redraw();
}
Ref<Texture2D> LineEdit::get_right_icon() {
	return right_icon;
}
void LineEdit::set_flat(bool p_enabled) {
	if (flat != p_enabled) {
		flat = p_enabled;
		queue_redraw();
	}
}
bool LineEdit::is_flat() const {
	return flat;
}
void LineEdit::set_select_all_on_focus(bool p_enabled) {
	select_all_on_focus = p_enabled;
}
bool LineEdit::is_select_all_on_focus() const {
	return select_all_on_focus;
}
void LineEdit::clear_pending_select_all_on_focus() {
	pending_select_all_on_focus = false;
}
void LineEdit::_text_changed() {