GLTFLoader: rename _q to _quaternion (#30917)

examples/jsm/loaders/GLTFLoader.js

@@ -2217,7 +2217,7 @@ class GLTFCubicSplineInterpolant extends Interpolant {
 
 }
 
-const _q = new Quaternion();
+const _quaternion = new Quaternion();
 
 class GLTFCubicSplineQuaternionInterpolant extends GLTFCubicSplineInterpolant {
 
@@ -2225,7 +2225,7 @@ class GLTFCubicSplineQuaternionInterpolant extends GLTFCubicSplineInterpolant {
 
 		const result = super.interpolate_( i1, t0, t, t1 );
 
-		_q.fromArray( result ).normalize().toArray( result );
+		_quaternion.fromArray( result ).normalize().toArray( result );
 
 		return result;