BatchedMesh: don't keep srcAttribute type and directly create BufferA…

…ttribute, omit usage (mrdoob#27978)

as sugested mrdoob#27973 (comment)

src/objects/BatchedMesh.js

@@ -195,8 +195,7 @@ class BatchedMesh extends Mesh {
 				const { array, itemSize, normalized } = srcAttribute;
 
 				const dstArray = new array.constructor( maxVertexCount * itemSize );
-				const dstAttribute = new srcAttribute.constructor( dstArray, itemSize, normalized );
-				dstAttribute.setUsage( srcAttribute.usage );
+				const dstAttribute = new BufferAttribute( dstArray, itemSize, normalized );
 
 				geometry.setAttribute( attributeName, dstAttribute );