### Godot version

v4.2.dev2.official [da81ca62a]

### System information

Godot v4.2.dev2 - Windows 10.0.19045 - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1060 6GB (NVIDIA; 31.0.15.3640) - Intel(R) Core(TM) i5-3570K CPU @ 3.40GHz (4 Threads)

### Issue description

If a freed node exists when editor breaks on breakpoint, Godot crashes. My guess is that debug view tries to show the freed node and somehow fails. If the freed node is set to null before the breakpoint, crash doesn't happen.

`v4.1.1.stable.official` works fine, but `v4.2.dev2.official` crashes.

### Steps to reproduce

```gdscript
extends Node2D

func _ready() -> void:
	var node = Node.new()
	node.free()

	#node = null  # uncomment this line to prevent crash

	pass # add breakpoint here to crash
```

### Minimal reproduction project

[g42_crash.zip](https://github.com/godotengine/godot/files/12300368/g42_crash.zip)

PropertyInfo pinfo;
	pinfo.name = type + n;
	pinfo.type = v.get_type();
	pinfo.hint = h;
	pinfo.hint_string = hs;
	variables->prop_list.push_back(pinfo);
	variables->prop_values[type + n] = v;
	variables->update();
	edit(variables);
	
	int size_x = get_size().x;
	if (size_x > get_custom_minimum_size().x) {
		set_custom_minimum_size(Size2(size_x, 0));
	}
}
void EditorDebuggerInspector::clear_stack_variables() {
	variables->clear();
	variables->update();
	set_custom_minimum_size(Size2(0, 0));
}
String EditorDebuggerInspector::get_stack_variable(const String &p_var) {
	for (KeyValue<StringName, Variant> &E : variables->prop_values) {
		String v = E.key.operator String();
		if (v.get_slice("/", 1) == p_var) {
			return variables->get_variant(v);
		}
	}
	return String();
}