### 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
GDEXTENSION_VARIANT_OP_AND,
	GDEXTENSION_VARIANT_OP_OR,
	GDEXTENSION_VARIANT_OP_XOR,
	GDEXTENSION_VARIANT_OP_NOT,
	
	GDEXTENSION_VARIANT_OP_IN,
	GDEXTENSION_VARIANT_OP_MAX
} GDExtensionVariantOperator;
typedef void *GDExtensionVariantPtr;
typedef const void *GDExtensionConstVariantPtr;
typedef void *GDExtensionUninitializedVariantPtr;
typedef void *GDExtensionStringNamePtr;
typedef const void *GDExtensionConstStringNamePtr;
typedef void *GDExtensionUninitializedStringNamePtr;
typedef void *GDExtensionStringPtr;
typedef const void *GDExtensionConstStringPtr;
typedef void *GDExtensionUninitializedStringPtr;
typedef void *GDExtensionObjectPtr;
typedef const void *GDExtensionConstObjectPtr;
typedef void *GDExtensionUninitializedObjectPtr;
typedef void *GDExtensionTypePtr;
typedef const void *GDExtensionConstTypePtr;
typedef void *GDExtensionUninitializedTypePtr;
typedef const void *GDExtensionMethodBindPtr;
typedef int64_t GDExtensionInt;
typedef uint8_t GDExtensionBool;
typedef uint64_t GDObjectInstanceID;
typedef void *GDExtensionRefPtr;
typedef const void *GDExtensionConstRefPtr;
typedef enum {