### 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 (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() {