### 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.
bool clipped = false;
					if (ofs_y + row_height < top_limit_y) {
						
						
						clipped = true;
					}
					if (ofs_y > bottom_limit_y) {
						
						i = draw_amount;
						break;
					}
					if (text.get_line_background_color(line) != Color(0, 0, 0, 0)) {
						if (rtl) {
							RenderingServer::get_singleton()->canvas_item_add_rect(ci, Rect2(size.width - ofs_x - xmargin_end, ofs_y, xmargin_end - xmargin_beg, row_height), text.get_line_background_color(line));
						} else {
							RenderingServer::get_singleton()->canvas_item_add_rect(ci, Rect2(xmargin_beg + ofs_x, ofs_y, xmargin_end - xmargin_beg, row_height), text.get_line_background_color(line));
						}
					}
					if (str.length() == 0) {
						
						if (caret_line_wrap_index_map.has(line) && caret_line_wrap_index_map[line].has(line_wrap_index) && highlight_current_line) {
							if (rtl) {
								RenderingServer::get_singleton()->canvas_item_add_rect(ci, Rect2(size.width - ofs_x - xmargin_end, ofs_y, xmargin_end, row_height), current_line_color);
							} else {
								RenderingServer::get_singleton()->canvas_item_add_rect(ci, Rect2(ofs_x, ofs_y, xmargin_end, row_height), current_line_color);
							}
						}
						
						for (int c = 0; c < carets.size(); c++) {
							if (has_selection(c) && line >= get_selection_from_line(c) && line <= get_selection_to_line(c) && char_margin >= xmargin_beg) {