### Godot version

4.1.beta1

### System information

macOS 13.3.1 mobile renderer

### Issue description

Trying to open and edit one of my visual shaders now consistently crashes Godot 4.1beta1. 

The shader was made and edited fine in earlier versions of Godot 4 and I'm not certain what is special with this shader (attached below for investigation). Opening and editing other visual shaders works fine for me. The only thing I can think of that this shader uses that other do not is the gradient node, though as I can't open it I'm not sure what else might be going on in it.

### Steps to reproduce

Open the attached visual shader (in any project)

### Minimal reproduction project

[ConnectBlendShader.tres.zip](https://www.lostminds.com/godot/ConnectBlendShader.tres.zip)
ERR_FAIL_COND(p_event.is_null());
	Ref<InputEventKey> k = p_event;
	if (k.is_valid()) {
		
		if (k->is_pressed() && k->get_keycode() == Key::KEY_DELETE) {
			if (selected_tangent_index != TANGENT_NONE) {
				toggle_linear(selected_index, selected_tangent_index);
			} else if (selected_index != -1) {
				if (grabbing == GRAB_ADD) {
					curve->remove_point(selected_index); 
					set_selected_index(-1);
				} else {
					remove_point(selected_index);
				}
				grabbing = GRAB_NONE;