### 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_caret, carets.size());
	if (!selecting_enabled) {
		return;
	}
	if (p_from_line < 0) {
		p_from_line = 0;
	} else if (p_from_line >= text.size()) {
		p_from_line = text.size() - 1;
	}
	if (p_from_column >= text[p_from_line].length()) {
		p_from_column = text[p_from_line].length();
	}
	if (p_from_column < 0) {
		p_from_column = 0;
	}
	if (p_to_line < 0) {
		p_to_line = 0;
	} else if (p_to_line >= text.size()) {
		p_to_line = text.size() - 1;
	}
	if (p_to_column >= text[p_to_line].length()) {