test: remove api mocks from link ms user spec (#54482)

Co-authored-by: Naomi <nhcarrigan@gmail.com>

e2e/link-ms-user.spec.ts

@@ -1,3 +1,5 @@
+import { execSync } from 'child_process';
+
 import { test, expect } from '@playwright/test';
 import translations from '../client/i18n/locales/english/translations.json';
 
@@ -38,6 +40,9 @@ test.describe('Link MS user component (signed-out user)', () => {
 });
 
 test.describe('Link MS user component (signed-in user)', () => {
+  test.afterEach(() => {
+    execSync('node ./tools/scripts/seed/seed-ms-username');
+  });
   test.use({ storageState: 'playwright/.auth/certified-user.json' });
 
   test("should recognize the user's MS account", async ({ page }) => {
@@ -48,23 +53,14 @@ test.describe('Link MS user component (signed-in user)', () => {
       })
     ).toBeVisible();
 
-    await expect(
-      page.getByText(
-        'The Microsoft account with username "certifieduser" is currently linked to your freeCodeCamp account. If this is not your Microsoft username, remove the link.'
-      )
-    ).toBeVisible();
+    await expect(page.locator('main')).toHaveText(
+      /The Microsoft account with username "certifieduser" is currently linked to your freeCodeCamp account\. If this is not your Microsoft username, remove the link\./
+    );
   });
 
   test('should allow the user to unlink their MS account and display a form for re-link', async ({
     page
   }) => {
-    // Intercept the endpoint to prevent `msUsername` from being deleted
-    // as the deletion will cause subsequent tests to fail
-    await page.route('*/**/user/ms-username', async route => {
-      const json = { msUsername: null };
-      await route.fulfill({ json });
-    });
-
     const unlinkButton = page.getByRole('button', {
       name: translations.buttons['unlink-account']
     });