### 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 (selection.enabled) {
		delete_text(selection.begin, selection.end);
	}
	deselect();
}
void LineEdit::set_max_length(int p_max_length) {
	ERR_FAIL_COND(p_max_length < 0);
	max_length = p_max_length;
	set_text(text);
}
int LineEdit::get_max_length() const {
	return max_length;
}
void LineEdit::selection_fill_at_caret() {
	if (!selecting_enabled) {
		return;
	}
	selection.begin = caret_column;
	selection.end = selection.start_column;
	if (selection.end < selection.begin) {
		int aux = selection.end;
		selection.end = selection.begin;
		selection.begin = aux;
	}
	selection.enabled = (selection.begin != selection.end);
}
void LineEdit::select_all() {