pdfjs: Make eslint happy about polyfills

qutebrowser/javascript/.eslintrc.yaml

@@ -62,3 +62,4 @@ rules:
     function-call-argument-newline: "off"
     no-negated-condition: "off"
     no-console: "off"
+    sort-vars: "off"

qutebrowser/javascript/pdfjs_polyfills.js

@@ -1,6 +1,9 @@
+/* eslint-disable strict */
+/* (this file gets used as a snippet) */
+
 (function() {
-    if (typeof Promise.withResolvers === 'undefined') {
-        Promise.withResolvers = function () {
+    if (typeof Promise.withResolvers === "undefined") {
+        Promise.withResolvers = function() {
             let resolve, reject
             const promise = new Promise((res, rej) => {
                 resolve = res