### 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_EQUAL,
	GDEXTENSION_VARIANT_OP_NOT_EQUAL,
	GDEXTENSION_VARIANT_OP_LESS,
	GDEXTENSION_VARIANT_OP_LESS_EQUAL,
	GDEXTENSION_VARIANT_OP_GREATER,
	GDEXTENSION_VARIANT_OP_GREATER_EQUAL,
	
	GDEXTENSION_VARIANT_OP_ADD,
	GDEXTENSION_VARIANT_OP_SUBTRACT,
	GDEXTENSION_VARIANT_OP_MULTIPLY,
	GDEXTENSION_VARIANT_OP_DIVIDE,
	GDEXTENSION_VARIANT_OP_NEGATE,
	GDEXTENSION_VARIANT_OP_POSITIVE,
	GDEXTENSION_VARIANT_OP_MODULE,
	GDEXTENSION_VARIANT_OP_POWER,
	
	GDEXTENSION_VARIANT_OP_SHIFT_LEFT,
	GDEXTENSION_VARIANT_OP_SHIFT_RIGHT,
	GDEXTENSION_VARIANT_OP_BIT_AND,
	GDEXTENSION_VARIANT_OP_BIT_OR,
	GDEXTENSION_VARIANT_OP_BIT_XOR,
	GDEXTENSION_VARIANT_OP_BIT_NEGATE,