### 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
_err_print_error(p_function, p_file, p_line, p_description, p_message, p_editor_notify, ERR_HANDLER_SCRIPT);
}
uint64_t gdextension_get_native_struct_size(GDExtensionConstStringNamePtr p_name) {
	const StringName name = *reinterpret_cast<const StringName *>(p_name);
	return ClassDB::get_native_struct_size(name);
}
static void gdextension_variant_new_copy(GDExtensionUninitializedVariantPtr r_dest, GDExtensionConstVariantPtr p_src) {
	memnew_placement(reinterpret_cast<Variant *>(r_dest), Variant(*reinterpret_cast<const Variant *>(p_src)));
}
static void gdextension_variant_new_nil(GDExtensionUninitializedVariantPtr r_dest) {
	memnew_placement(reinterpret_cast<Variant *>(r_dest), Variant);
}
static void gdextension_variant_destroy(GDExtensionVariantPtr p_self) {
	reinterpret_cast<Variant *>(p_self)->~Variant();
}
static void gdextension_variant_call(GDExtensionVariantPtr p_self, GDExtensionConstStringNamePtr p_method, const GDExtensionConstVariantPtr *p_args, GDExtensionInt p_argcount, GDExtensionUninitializedVariantPtr r_return, GDExtensionCallError *r_error) {
	Variant *self = (Variant *)p_self;
	const StringName method = *reinterpret_cast<const StringName *>(p_method);
	const Variant **args = (const Variant **)p_args;
	Callable::CallError error;
	memnew_placement(r_return, Variant);
	Variant *ret = reinterpret_cast<Variant *>(r_return);
	self->callp(method, args, p_argcount, *ret, error);
	if (r_error) {
		r_error->error = (GDExtensionCallErrorType)(error.error);
		r_error->argument = error.argument;
		r_error->expected = error.expected;
	}
}
static void gdextension_variant_call_static(GDExtensionVariantType p_type, GDExtensionConstStringNamePtr p_method, const GDExtensionConstVariantPtr *p_args, GDExtensionInt p_argcount, GDExtensionUninitializedVariantPtr r_return, GDExtensionCallError *r_error) {