TS: fix KeyframeTrack constructor types

[vickyliin]

Description

KeyframeTrack's type definition only allows Arrays to pass in for times & values parameters,
but as I need to pass Float32Array, I found they might actually support any record in number key type.

three.js/src/animation/AnimationUtils.js

Lines 22 to 35 in f3bfe7d

	convertArray: function ( array, type, forceClone ) {
	if ( ! array || // let 'undefined' and 'null' pass
	! forceClone && array.constructor === type ) return array;
	if ( typeof type.BYTES_PER_ELEMENT === 'number' ) {
	return new type( array ); // create typed array
	}
	return Array.prototype.slice.call( array ); // create Array
	},

[mrdoob]

Thanks!