Fixes #1305: avoid pointing to missing source maps

gulpfile.js

@@ -317,6 +317,8 @@ function ESM_pluginStream(plugin, destinationPath) {
 				}
 			}
 
+			contents = contents.replace(/\/\/# sourceMappingURL=.*((\r?\n)|$)/g, '');
+
 			data.contents = Buffer.from(contents);
 			this.emit('data', data);
 		}))