wait for the promise to be resolved

lib/single-file/single-file-core.js

@@ -827,9 +827,9 @@ this.SingleFileCore = this.SingleFileCore || (() => {
 		}
 
 		async processStylesheets() {
-			await Promise.all(Array.from(this.stylesheets).map(([, stylesheetInfo]) => {
-				ProcessorHelper.processStylesheet(stylesheetInfo.stylesheet.children, this.baseURI, this.options, this.cssVariables, this.batchRequest);
-			}));
+			await Promise.all(Array.from(this.stylesheets).map(([, stylesheetInfo]) =>
+				ProcessorHelper.processStylesheet(stylesheetInfo.stylesheet.children, this.baseURI, this.options, this.cssVariables, this.batchRequest)
+			));
 		}
 
 		replaceStylesheets() {