### 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
typedef void (*GDExtensionPtrKeyedSetter)(GDExtensionTypePtr p_base, GDExtensionConstTypePtr p_key, GDExtensionConstTypePtr p_value);
typedef void (*GDExtensionPtrKeyedGetter)(GDExtensionConstTypePtr p_base, GDExtensionConstTypePtr p_key, GDExtensionTypePtr r_value);
typedef uint32_t (*GDExtensionPtrKeyedChecker)(GDExtensionConstVariantPtr p_base, GDExtensionConstVariantPtr p_key);
typedef void (*GDExtensionPtrUtilityFunction)(GDExtensionTypePtr r_return, const GDExtensionConstTypePtr *p_args, int p_argument_count);
typedef GDExtensionObjectPtr (*GDExtensionClassConstructor)();
typedef void *(*GDExtensionInstanceBindingCreateCallback)(void *p_token, void *p_instance);
typedef void (*GDExtensionInstanceBindingFreeCallback)(void *p_token, void *p_instance, void *p_binding);
typedef GDExtensionBool (*GDExtensionInstanceBindingReferenceCallback)(void *p_token, void *p_binding, GDExtensionBool p_reference);
typedef struct {
	GDExtensionInstanceBindingCreateCallback create_callback;
	GDExtensionInstanceBindingFreeCallback free_callback;
	GDExtensionInstanceBindingReferenceCallback reference_callback;
} GDExtensionInstanceBindingCallbacks;
typedef void *GDExtensionClassInstancePtr;
typedef GDExtensionBool (*GDExtensionClassSet)(GDExtensionClassInstancePtr p_instance, GDExtensionConstStringNamePtr p_name, GDExtensionConstVariantPtr p_value);
typedef GDExtensionBool (*GDExtensionClassGet)(GDExtensionClassInstancePtr p_instance, GDExtensionConstStringNamePtr p_name, GDExtensionVariantPtr r_ret);
typedef uint64_t (*GDExtensionClassGetRID)(GDExtensionClassInstancePtr p_instance);
typedef struct {
	GDExtensionVariantType type;
	GDExtensionStringNamePtr name;
	GDExtensionStringNamePtr class_name;
	uint32_t hint; 
	GDExtensionStringPtr hint_string;
	uint32_t usage; 
} GDExtensionPropertyInfo;
typedef struct {
	GDExtensionStringNamePtr name;
	GDExtensionPropertyInfo return_value;
	uint32_t flags; 
	int32_t id;