### 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 (editable && selection.enabled && !pass) {
		DisplayServer::get_singleton()->clipboard_set(text.substr(selection.begin, selection.end - selection.begin));
		selection_delete();
	}
}
void LineEdit::paste_text() {
	if (!editable) {
		return;
	}
	
	String paste_buffer = DisplayServer::get_singleton()->clipboard_get().strip_escapes();
	if (!paste_buffer.is_empty()) {
		int prev_len = text.length();
		if (selection.enabled) {
			selection_delete();
		}
		insert_text_at_caret(paste_buffer);
		if (!text_changed_dirty) {
			if (is_inside_tree() && text.length() != prev_len) {
				MessageQueue::get_singleton()->push_call(this, "_text_changed");
			}
			text_changed_dirty = true;
		}
	}
}
bool LineEdit::has_undo() const {