### Godot version

4.1.1

### System information

Meta Quest 2 - GLES3

### Issue description

When writing VR applications on Godot 4 using gl_compatibility, skeleton-driven meshes like hands are often rendered corrupted, or sometimes update slowly.

### Steps to reproduce

The godot-xr-tools demo projects have these issues in the climbing/gliding and pointer-demo scenes if the project is switched to gl_compatibility mode and run on a mobile VR headset.

### Minimal reproduction project

The godot-xr-tools demo project has been the testing project for this issue.
MultiMesh *multimesh = multimesh_owner.get_or_null(p_multimesh);
	ERR_FAIL_COND(!multimesh);
	ERR_FAIL_INDEX(p_index, multimesh->instances);
	ERR_FAIL_COND(!multimesh->uses_custom_data);
	_multimesh_make_local(multimesh);
	{
		float *w = multimesh->data_cache.ptrw();
		float *dataptr = w + p_index * multimesh->stride_cache + multimesh->custom_data_offset_cache;
		uint16_t val[4] = { Math::make_half_float(p_color.r), Math::make_half_float(p_color.g), Math::make_half_float(p_color.b), Math::make_half_float(p_color.a) };
		memcpy(dataptr, val, 2 * 4);
	}
	_multimesh_mark_dirty(multimesh, p_index, false);
}
RID MeshStorage::multimesh_get_mesh(RID p_multimesh) const {
	MultiMesh *multimesh = multimesh_owner.get_or_null(p_multimesh);
	ERR_FAIL_COND_V(!multimesh, RID());
	return multimesh->mesh;
}
AABB MeshStorage::multimesh_get_aabb(RID p_multimesh) const {
	MultiMesh *multimesh = multimesh_owner.get_or_null(p_multimesh);
	ERR_FAIL_COND_V(!multimesh, AABB());
	if (multimesh->aabb_dirty) {
		const_cast<MeshStorage *>(this)->_update_dirty_multimeshes();
	}
	return multimesh->aabb;
}
Transform3D MeshStorage::multimesh_instance_get_transform(RID p_multimesh, int p_index) const {