### 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
GDExtensionClassToString to_string_func;
	GDExtensionClassReference reference_func;
	GDExtensionClassUnreference unreference_func;
	GDExtensionClassCreateInstance create_instance_func; 
	GDExtensionClassFreeInstance free_instance_func; 
	GDExtensionClassGetVirtual get_virtual_func; 
	GDExtensionClassGetRID get_rid_func;
	void *class_userdata; 
} GDExtensionClassCreationInfo; 
typedef struct {
	GDExtensionBool is_virtual;
	GDExtensionBool is_abstract;
	GDExtensionClassSet set_func;
	GDExtensionClassGet get_func;
	GDExtensionClassGetPropertyList get_property_list_func;
	GDExtensionClassFreePropertyList free_property_list_func;
	GDExtensionClassPropertyCanRevert property_can_revert_func;
	GDExtensionClassPropertyGetRevert property_get_revert_func;
	GDExtensionClassNotification2 notification_func;
	GDExtensionClassToString to_string_func;
	GDExtensionClassReference reference_func;
	GDExtensionClassUnreference unreference_func;
	GDExtensionClassCreateInstance create_instance_func; 
	GDExtensionClassFreeInstance free_instance_func; 
	GDExtensionClassGetVirtual get_virtual_func; 
	GDExtensionClassGetRID get_rid_func;
	void *class_userdata; 
} GDExtensionClassCreationInfo2;
typedef void *GDExtensionClassLibraryPtr;
typedef enum {