### 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?)
undo_redo->add_do_method(this, "_clear_selection_for_anim", animation);
	undo_redo->add_undo_method(this, "_clear_selection_for_anim", animation);
	
	for (RBMap<SelectedKey, KeyInfo>::Element *E = selection.back(); E; E = E->prev()) {
		float oldpos = E->get().pos;
		float newpos = snap_time(oldpos + motion);
		undo_redo->add_do_method(this, "_select_at_anim", animation, E->key().track, newpos);
		undo_redo->add_undo_method(this, "_select_at_anim", animation, E->key().track, oldpos);
	}
	moving_selection = false;
	undo_redo->add_do_method(this, "_redraw_tracks");
	undo_redo->add_undo_method(this, "_redraw_tracks");
	undo_redo->commit_action();
}
void AnimationTrackEditor::_move_selection_cancel() {
	moving_selection = false;
	_redraw_tracks();
}
bool AnimationTrackEditor::is_moving_selection() const {
	return moving_selection;
}
float AnimationTrackEditor::get_moving_selection_offset() const {
	return moving_selection_offset;
}
void AnimationTrackEditor::_box_selection_draw() {
	const Rect2 selection_rect = Rect2(Point2(), box_selection->get_size());
	box_selection->draw_rect(selection_rect, get_theme_color(SNAME("box_selection_fill_color"), SNAME("Editor")));
	box_selection->draw_rect(selection_rect, get_theme_color(SNAME("box_selection_stroke_color"), SNAME("Editor")), false, Math::round(EDSCALE));
}
void AnimationTrackEditor::_scroll_input(const Ref<InputEvent> &p_event) {