MM-63451 Rely on MUI's MenuList to handle focus when opening menus (#30585)

* MM-63451 Rely on MUI's MenuList to handle focus when opening menus

* MM-63451 Add E2E tests for keyboard accessibility in the account menu

* Run prettier on E2E tests

* And check in the rest of those changes

* Fix lint

e2e-tests/playwright/lib/src/ui/components/global_header.ts

@@ -6,6 +6,7 @@ import {Locator, expect} from '@playwright/test';
 export default class GlobalHeader {
     readonly container: Locator;
 
+    readonly accountMenuButton;
     readonly productSwitchMenu;
     readonly recentMentionsButton;
     readonly settingsButton;
@@ -14,6 +15,7 @@ export default class GlobalHeader {
     constructor(container: Locator) {
         this.container = container;
 
+        this.accountMenuButton = container.getByRole('button', {name: "'s account menu"});
         this.productSwitchMenu = container.getByRole('button', {name: 'Product switch menu'});
         this.recentMentionsButton = container.getByRole('button', {name: 'Recent mentions'});
         this.settingsButton = container.getByRole('button', {name: 'Settings'});