### 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.
menu_ctl->add_item(RTR("Soft Hyphen (SHY)"), MENU_INSERT_SHY);
		menu->add_child(menu_ctl, false, INTERNAL_MODE_FRONT);
		menu->connect("id_pressed", callable_mp(this, &LineEdit::menu_option));
		menu->connect(SNAME("focus_entered"), callable_mp(this, &LineEdit::_validate_caret_can_draw));
		menu->connect(SNAME("focus_exited"), callable_mp(this, &LineEdit::_validate_caret_can_draw));
		menu_dir->connect("id_pressed", callable_mp(this, &LineEdit::menu_option));
		menu_ctl->connect("id_pressed", callable_mp(this, &LineEdit::menu_option));
	}
	
	menu->clear();
	if (editable) {
		menu->add_item(RTR("Cut"), MENU_CUT, is_shortcut_keys_enabled() ? _get_menu_action_accelerator("ui_cut") : Key::NONE);
	}
	menu->add_item(RTR("Copy"), MENU_COPY, is_shortcut_keys_enabled() ? _get_menu_action_accelerator("ui_copy") : Key::NONE);
	if (editable) {
		menu->add_item(RTR("Paste"), MENU_PASTE, is_shortcut_keys_enabled() ? _get_menu_action_accelerator("ui_paste") : Key::NONE);
	}
	menu->add_separator();
	if (is_selecting_enabled()) {
		menu->add_item(RTR("Select All"), MENU_SELECT_ALL, is_shortcut_keys_enabled() ? _get_menu_action_accelerator("ui_text_select_all") : Key::NONE);
	}
	if (editable) {
		menu->add_item(RTR("Clear"), MENU_CLEAR);
		menu->add_separator();
		menu->add_item(RTR("Undo"), MENU_UNDO, is_shortcut_keys_enabled() ? _get_menu_action_accelerator("ui_undo") : Key::NONE);
		menu->add_item(RTR("Redo"), MENU_REDO, is_shortcut_keys_enabled() ? _get_menu_action_accelerator("ui_redo") : Key::NONE);
	}
	menu->add_separator();
	menu->add_submenu_item(RTR("Text Writing Direction"), "DirMenu");
	menu->add_separator();