### 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
*
 * @param p_library A pointer the library received by the GDExtension's entry point function.
 * @param r_path A pointer to a String which will receive the path.
 */
typedef void (*GDExtensionInterfaceGetLibraryPath)(GDExtensionClassLibraryPtr p_library, GDExtensionUninitializedStringPtr r_path);
/**
 * @name editor_add_plugin
 * @since 4.1
 *
 * Adds an editor plugin.
 *
 * It's safe to call during initialization.
 *
 * @param p_class_name A pointer to a StringName with the name of a class (descending from EditorPlugin) which is already registered with ClassDB.
 */
typedef void (*GDExtensionInterfaceEditorAddPlugin)(GDExtensionConstStringNamePtr p_class_name);
/**
 * @name editor_remove_plugin
 * @since 4.1
 *
 * Removes an editor plugin.
 *
 * @param p_class_name A pointer to a StringName with the name of a class that was previously added as an editor plugin.
 */
typedef void (*GDExtensionInterfaceEditorRemovePlugin)(GDExtensionConstStringNamePtr p_class_name);
#ifdef __cplusplus
}
#endif
#endif