### Godot version

4.0.dev (c309de53997feff3286295fb2d71657f112a15db)

### System information

Linux, Nvidia, Vulkan

### Issue description

Editor segfaults when certain conditions are met when using the AnimationPlayer editor.

### Steps to reproduce

1. Create multiple animations, saved into a animation collection
2. Open an existing animation, then make a new empty animation
3. Change from seconds to fps, or add a new property to animate ()
4. Editor crashes

NOTE: It is slightly random and I have not found a perfect repro

### Minimal reproduction project

N/A (TBD?)
if (mb->is_command_or_control_pressed() || mb->is_shift_pressed()) {
						if (editor->is_key_selected(track, key_idx)) {
							emit_signal(SNAME("deselect_key"), key_idx);
						} else {
							emit_signal(SNAME("select_key"), key_idx, false);
							moving_selection_attempt = true;
							select_single_attempt = -1;
							moving_selection_from_ofs = (mb->get_position().x - limit) / timeline->get_zoom_scale();
						}
					} else {
						if (!editor->is_key_selected(track, key_idx)) {
							emit_signal(SNAME("select_key"), key_idx, true);
							select_single_attempt = -1;
						} else {
							select_single_attempt = key_idx;
						}
						moving_selection_attempt = true;
						moving_selection_from_ofs = (mb->get_position().x - limit) / timeline->get_zoom_scale();
					}
					if (read_only) {
						moving_selection_attempt = false;
						moving_selection_from_ofs = 0.0f;
					}
					accept_event();
				}
			}
		}
	}
	if (mb.is_valid() && mb->is_pressed() && mb->get_button_index() == MouseButton::RIGHT) {
		Point2 pos = mb->get_position();