### 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_V(!multimesh, Transform2D());
	ERR_FAIL_INDEX_V(p_index, multimesh->instances, Transform2D());
	ERR_FAIL_COND_V(multimesh->xform_format != RS::MULTIMESH_TRANSFORM_2D, Transform2D());
	_multimesh_make_local(multimesh);
	Transform2D t;
	{
		const float *r = multimesh->data_cache.ptr();
		const float *dataptr = r + p_index * multimesh->stride_cache;
		t.columns[0][0] = dataptr[0];
		t.columns[1][0] = dataptr[1];
		t.columns[2][0] = dataptr[3];
		t.columns[0][1] = dataptr[4];
		t.columns[1][1] = dataptr[5];
		t.columns[2][1] = dataptr[7];
	}
	return t;
}
Color MeshStorage::multimesh_instance_get_color(RID p_multimesh, int p_index) const {