### Godot version

4.0 beta 15

### System information

Windows 10

### Issue description

It happened with both Google IME and MS-IME, and there was no problem until Beta14.
When typing Japanese characters, it is common to select a character from the suggestion window and then start typing the next character before confirming.
In this case, uncommitted characters are forcibly committed, and input of the next character begins.

**↓Beta15**

https://user-images.githubusercontent.com/186786/214753450-b493cca6-2644-4b3d-8cd2-660565cc3547.mp4

**↓Beta14**

https://user-images.githubusercontent.com/186786/214755127-dde819cc-4d63-403a-99b0-09821671f74e.mp4



### Steps to reproduce

It happened with both Google IME and MS-IME in beta15

### Minimal reproduction project

It is project independent and happens in the editor.
ERR_FAIL_INDEX(p_line, text.size());
	if (font.is_null()) {
		return; 
	}
	if (p_text_changed) {
		text.write[p_line].data_buf->clear();
	}
	text.write[p_line].data_buf->set_width(width);
	text.write[p_line].data_buf->set_direction((TextServer::Direction)direction);
	text.write[p_line].data_buf->set_preserve_control(draw_control_chars);
	if (p_ime_text.length() > 0) {
		if (p_text_changed) {
			text.write[p_line].data_buf->add_string(p_ime_text, font, font_size, language);
		}
		if (!p_bidi_override.is_empty()) {
			TS->shaped_text_set_bidi_override(text.write[p_line].data_buf->get_rid(), p_bidi_override);
		}
	} else {
		if (p_text_changed) {
			text.write[p_line].data_buf->add_string(text[p_line].data, font, font_size, language);
		}
		if (!text[p_line].bidi_override.is_empty()) {
			TS->shaped_text_set_bidi_override(text.write[p_line].data_buf->get_rid(), text[p_line].bidi_override);
		}
	}