### 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
info_2->get_method_list_func = p_info->get_method_list_func;
	info_2->free_method_list_func = p_info->free_method_list_func;
	info_2->get_property_type_func = p_info->get_property_type_func;
	info_2->has_method_func = p_info->has_method_func;
	info_2->call_func = p_info->call_func;
	info_2->notification_func = nullptr;
	info_2->to_string_func = p_info->to_string_func;
	info_2->refcount_incremented_func = p_info->refcount_incremented_func;
	info_2->refcount_decremented_func = p_info->refcount_decremented_func;
	info_2->get_script_func = p_info->get_script_func;
	info_2->is_placeholder_func = p_info->is_placeholder_func;
	info_2->set_fallback_func = p_info->set_fallback_func;
	info_2->get_fallback_func = p_info->get_fallback_func;
	info_2->get_language_func = p_info->get_language_func;
	info_2->free_func = p_info->free_func;
	ScriptInstanceExtension *script_instance_extension = memnew(ScriptInstanceExtension);
	script_instance_extension->instance = p_instance_data;
	script_instance_extension->native_info = info_2;
	script_instance_extension->free_native_info = true;
	script_instance_extension->deprecated_native_info.notification_func = p_info->notification_func;
	return reinterpret_cast<GDExtensionScriptInstancePtr>(script_instance_extension);
}
#endif 
static GDExtensionScriptInstancePtr gdextension_script_instance_create2(const GDExtensionScriptInstanceInfo2 *p_info, GDExtensionScriptInstanceDataPtr p_instance_data) {
	ScriptInstanceExtension *script_instance_extension = memnew(ScriptInstanceExtension);
	script_instance_extension->instance = p_instance_data;
	script_instance_extension->native_info = p_info;
	return reinterpret_cast<GDExtensionScriptInstancePtr>(script_instance_extension);
}
static GDExtensionScriptInstancePtr gdextension_placeholder_script_instance_create(GDExtensionObjectPtr p_language, GDExtensionObjectPtr p_script, GDExtensionObjectPtr p_owner) {