### 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
* @since 4.1
 *
 * Gets a const pointer to a Variant in an Array.
 *
 * @param p_self A const pointer to an Array object.
 * @param p_index The index of the Variant to get.
 *
 * @return A const pointer to the requested Variant.
 */
typedef GDExtensionVariantPtr (*GDExtensionInterfaceArrayOperatorIndexConst)(GDExtensionConstTypePtr p_self, GDExtensionInt p_index);
/**
 * @name array_ref
 * @since 4.1
 *
 * Sets an Array to be a reference to another Array object.
 *
 * @param p_self A pointer to the Array object to update.
 * @param p_from A pointer to the Array object to reference.
 */
typedef void (*GDExtensionInterfaceArrayRef)(GDExtensionTypePtr p_self, GDExtensionConstTypePtr p_from);
/**
 * @name array_set_typed
 * @since 4.1
 *
 * Makes an Array into a typed Array.
 *
 * @param p_self A pointer to the Array.
 * @param p_type The type of Variant the Array will store.
 * @param p_class_name A pointer to a StringName with the name of the object (if p_type is GDEXTENSION_VARIANT_TYPE_OBJECT).
 * @param p_script A pointer to a Script object (if p_type is GDEXTENSION_VARIANT_TYPE_OBJECT and the base class is extended by a script).