### 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
* Opens a raw XML buffer on an XMLParser instance.
 *
 * @param p_instance A pointer to an XMLParser object.
 * @param p_buffer A pointer to the buffer.
 * @param p_size The size of the buffer.
 *
 * @return A Godot error code (ex. OK, ERR_INVALID_DATA, etc).
 *
 * @see XMLParser::open_buffer()
 */
typedef GDExtensionInt (*GDExtensionInterfaceXmlParserOpenBuffer)(GDExtensionObjectPtr p_instance, const uint8_t *p_buffer, size_t p_size);
/**
 * @name file_access_store_buffer
 * @since 4.1
 *
 * Stores the given buffer using an instance of FileAccess.
 *
 * @param p_instance A pointer to a FileAccess object.
 * @param p_src A pointer to the buffer.
 * @param p_length The size of the buffer.
 *
 * @see FileAccess::store_buffer()
 */
typedef void (*GDExtensionInterfaceFileAccessStoreBuffer)(GDExtensionObjectPtr p_instance, const uint8_t *p_src, uint64_t p_length);
/**
 * @name file_access_get_buffer
 * @since 4.1
 *
 * Reads the next p_length bytes into the given buffer using an instance of FileAccess.
 *