fix (1.0, springBone): remove Object.freeze

using `Object.freeze` on Quaternion makes the quaternion type imcompatible because of iterator

It seems to be a bug of TypeScript which is already fixed in the latest version
See: microsoft/TypeScript#42543

packages/three-vrm-springbone/src/VRMSpringBoneJoint.ts

@@ -9,8 +9,8 @@ import type { VRMSpringBoneJointSettings } from './VRMSpringBoneJointSettings';
 // http://rocketjump.skr.jp/unity3d/109/
 // https://github.com/dwango/UniVRM/blob/master/Scripts/SpringBone/VRMSpringBone.cs
 
-const IDENTITY_MATRIX4 = Object.freeze(new THREE.Matrix4());
-const IDENTITY_QUATERNION = Object.freeze(new THREE.Quaternion());
+const IDENTITY_MATRIX4 = new THREE.Matrix4();
+const IDENTITY_QUATERNION = new THREE.Quaternion();
 
 // 計算中の一時保存用変数（一度インスタンスを作ったらあとは使い回す）
 const _v3A = new THREE.Vector3();