### 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_V(p_line, text.size(), false);
	return text.is_hidden(p_line);
}
void TextEdit::_unhide_all_lines() {
	for (int i = 0; i < text.size(); i++) {
		text.set_hidden(i, false);
	}
	_update_scrollbars();
	queue_redraw();
}
void TextEdit::_set_line_as_hidden(int p_line, bool p_hidden) {
	ERR_FAIL_INDEX(p_line, text.size());
	if (text.is_hidden(p_line) == p_hidden) {
		return;
	}
	if (_is_hiding_enabled() || !p_hidden) {
		text.set_hidden(p_line, p_hidden);
	}
	queue_redraw();
}
void TextEdit::_set_symbol_lookup_word(const String &p_symbol) {
	if (lookup_symbol_word == p_symbol) {
		return;
	}
	lookup_symbol_word = p_symbol;
	queue_redraw();
}
void TextEdit::_handle_unicode_input_internal(const uint32_t p_unicode, int p_caret) {