KTX2Loader: Honor `setRequestHeader()`. (#32115)

* Honor setRequestHeader() in KTX2Loader

Configure the internal loader to use the same request header of its owner

* Formatted code

examples/jsm/loaders/KTX2Loader.js

@@ -359,6 +359,7 @@ class KTX2Loader extends Loader {
 		loader.setPath( this.path );
 		loader.setCrossOrigin( this.crossOrigin );
 		loader.setWithCredentials( this.withCredentials );
+		loader.setRequestHeader( this.requestHeader );
 		loader.setResponseType( 'arraybuffer' );
 
 		loader.load( url, ( buffer ) => {