### Godot version

4.2 247c354

### System information

Windows 10.0.19045 - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1060 (NVIDIA; 30.0.15.1403) - Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz (8 Threads)

### Issue description

#75778 exposed `_validate_property()` to scripting. It's implemented in GDScript and C#, but not GDExtension (depends on #78634).
https://github.com/godotengine/godot/blob/247c3548d810136ffe9c1694cd76db3236efaa90/core/object/script_language_extension.h#L685-L687

Relevant discussion: https://github.com/godotengine/godot/pull/75778#discussion_r1307294940

### Steps to reproduce

1. Add GDExtension script
2. Use `_validate_property()`

### Minimal reproduction project

N/A
const Array *self = (const Array *)p_self;
	if (unlikely(p_index < 0 || p_index >= self->size())) {
		return nullptr;
	}
	return (GDExtensionVariantPtr)&self->operator[](p_index);
}
void gdextension_array_ref(GDExtensionTypePtr p_self, GDExtensionConstTypePtr p_from) {
	Array *self = (Array *)p_self;
	const Array *from = (const Array *)p_from;
	self->_ref(*from);
}
void gdextension_array_set_typed(GDExtensionTypePtr p_self, GDExtensionVariantType p_type, GDExtensionConstStringNamePtr p_class_name, GDExtensionConstVariantPtr p_script) {
	Array *self = reinterpret_cast<Array *>(p_self);
	const StringName *class_name = reinterpret_cast<const StringName *>(p_class_name);
	const Variant *script = reinterpret_cast<const Variant *>(p_script);
	self->set_typed((uint32_t)p_type, *class_name, *script);
}
static GDExtensionVariantPtr gdextension_dictionary_operator_index(GDExtensionTypePtr p_self, GDExtensionConstVariantPtr p_key) {
	Dictionary *self = (Dictionary *)p_self;
	return (GDExtensionVariantPtr)&self->operator[](*(const Variant *)p_key);
}
static GDExtensionVariantPtr gdextension_dictionary_operator_index_const(GDExtensionConstTypePtr p_self, GDExtensionConstVariantPtr p_key) {
	const Dictionary *self = (const Dictionary *)p_self;
	return (GDExtensionVariantPtr)&self->operator[](*(const Variant *)p_key);
}
static void gdextension_object_method_bind_call(GDExtensionMethodBindPtr p_method_bind, GDExtensionObjectPtr p_instance, const GDExtensionConstVariantPtr *p_args, GDExtensionInt p_arg_count, GDExtensionUninitializedVariantPtr r_return, GDExtensionCallError *r_error) {