GDScript: no parser error when invalid preload() used

[ThakeeNathees]

Godot version: v4.0.dev.custom_build 5ba46dd

OS/device including version: windows 10

Issue description:
preloading the current script doesn't show any errors.

extends Node2D
## current script path = res://Node2D.gd
var s = preload("res://Node2D.gd")

[adamscott]

Since #67714, it's actually a feature. A script can preload itself, then compare the type.
So this code works:

# res://A.gd
var SelfClass: = preload("res://A.gd")

func _ready() -> void:
    print(is_instance_of(self, SelfClass))  # true