### 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.
float text_width = TS->shaped_text_get_size(text_rid).x;
			float text_height = TS->shaped_text_get_size(text_rid).y;
			switch (alignment) {
				case HORIZONTAL_ALIGNMENT_FILL:
				case HORIZONTAL_ALIGNMENT_LEFT: {
					if (rtl) {
						x_ofs = MAX(style->get_margin(SIDE_LEFT), int(size.width - Math::ceil(style->get_margin(SIDE_RIGHT) + (text_width))));
					} else {
						x_ofs = style->get_offset().x;
					}
				} break;
				case HORIZONTAL_ALIGNMENT_CENTER: {
					if (!Math::is_zero_approx(scroll_offset)) {
						x_ofs = style->get_offset().x;
					} else {
						x_ofs = MAX(style->get_margin(SIDE_LEFT), int(size.width - (text_width)) / 2);
					}
				} break;
				case HORIZONTAL_ALIGNMENT_RIGHT: {
					if (rtl) {
						x_ofs = style->get_offset().x;
					} else {
						x_ofs = MAX(style->get_margin(SIDE_LEFT), int(size.width - Math::ceil(style->get_margin(SIDE_RIGHT) + (text_width))));
					}
				} break;
			}
			int ofs_max = width - style->get_margin(SIDE_RIGHT);
			int y_area = height - style->get_minimum_size().height;
			int y_ofs = style->get_offset().y + (y_area - text_height) / 2;
			Color selection_color = theme_cache.selection_color;