Delete invalid and outdated fallback (#30744)

examples/jsm/exporters/GLTFExporter.js

@@ -1465,25 +1465,7 @@ class GLTFWriter {
 
 			} else {
 
-				if ( canvas.toDataURL !== undefined ) {
-
-					imageDef.uri = canvas.toDataURL( mimeType );
-
-				} else {
-
-					pending.push(
-
-						getToBlobPromise( canvas, mimeType )
-							.then( blob => new FileReader().readAsDataURL( blob ) )
-							.then( dataURL => {
-
-								imageDef.uri = dataURL;
-
-							} )
-
-					);
-
-				}
+				imageDef.uri = canvas.toDataURL( mimeType );
 
 			}