### 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 (color != previous_color) {
									characters--;
									j--;
									if (str[j] == '\t') {
										tabs -= minimap_tab_size;
									}
								}
							}
							if (characters > 0) {
								previous_color.a *= 0.6;
								
								int chars = MAX(0, (j - (characters - 1)) - (whitespace ? 1 : 0)) + 1;
								int char_x_ofs = indent_px + ((xmargin_end + minimap_char_size.x) + (minimap_char_size.x * chars)) + tabs;
								if (rtl) {
									RenderingServer::get_singleton()->canvas_item_add_rect(ci, Rect2(Point2(size.width - char_x_ofs - minimap_char_size.x * characters, minimap_line_height * i), Point2(minimap_char_size.x * characters, minimap_char_size.y)), previous_color);
								} else {
									RenderingServer::get_singleton()->canvas_item_add_rect(ci, Rect2(Point2(char_x_ofs, minimap_line_height * i), Point2(minimap_char_size.x * characters, minimap_char_size.y)), previous_color);
								}
							}
							if (out_of_bounds) {
								break;
							}
							if (str[j] == '\t') {
								tabs += minimap_tab_size;
							}
							previous_color = color;
							characters = 0;
						}
					}