✅(e2e) increase timeout doc export test

We have a test asserting lot of things on the doc
export, and it's failing on CI because of the
timeout.
We increase the timeout to make it pass.

src/frontend/apps/e2e/__tests__/app-impress/doc-export.spec.ts

@@ -85,6 +85,8 @@ test.describe('Doc Export', () => {
     page,
     browserName,
   }) => {
+    test.slow();
+
     const [randomDoc] = await createDoc(page, 'doc-editor', browserName, 1);
     let body = '';
 
@@ -148,6 +150,9 @@ test.describe('Doc Export', () => {
       .last()
       .fill('Test List 3');
 
+    await page.keyboard.press('Enter');
+    await page.keyboard.press('Backspace');
+
     // Add a number list
     await page.locator('.bn-block-outer').last().click();
     await page.keyboard.press('Enter');