### 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.
if (font == p_font) {
		return;
	}
	font = p_font;
	is_dirty = true;
}
void TextEdit::Text::set_font_size(int p_font_size) {
	if (font_size == p_font_size) {
		return;
	}
	font_size = p_font_size;
	is_dirty = true;
}
void TextEdit::Text::set_tab_size(int p_tab_size) {
	if (tab_size == p_tab_size) {
		return;
	}
	tab_size = p_tab_size;
	tab_size_dirty = true;
}
int TextEdit::Text::get_tab_size() const {