Enable the ESLint object-shorthand rule in the extensions/chromium/-folder

Based on the following compatibility information, there can't be any compelling reason to not enable this ESLint rule now: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Object_initializer#browser_compatibility

See also https://eslint.org/docs/rules/object-shorthand

extensions/chromium/pdfHandler.js

@@ -242,12 +242,12 @@ chrome.runtime.onMessage.addListener(function (message, sender, sendResponse) {
       chrome.tabs.create({
         windowId: sender.tab.windowId,
         index: sender.tab.index + 1,
-        url: url,
+        url,
         openerTabId: sender.tab.id,
       });
     } else {
       chrome.tabs.update(sender.tab.id, {
-        url: url,
+        url,
       });
     }
   }