GLTFLoader: Add KTX2 mime type support in getImageURIMimeType (#29746)

examples/jsm/loaders/GLTFLoader.js

@@ -2525,6 +2525,7 @@ function getImageURIMimeType( uri ) {
 
 	if ( uri.search( /\.jpe?g($|\?)/i ) > 0 || uri.search( /^data\:image\/jpeg/ ) === 0 ) return 'image/jpeg';
 	if ( uri.search( /\.webp($|\?)/i ) > 0 || uri.search( /^data\:image\/webp/ ) === 0 ) return 'image/webp';
+	if ( uri.search( /\.ktx2($|\?)/i ) > 0 || uri.search( /^data\:image\/ktx2/ ) === 0 ) return 'image/ktx2';
 
 	return 'image/png';