test: fix flaky lexical code block test with incorrect error expectations (#15776)

### What

Fixed flaky e2e test for lexical code blocks that was consistently
failing in CI and locally.

<img width="1335" height="607" alt="Screenshot 2026-02-26 at 2 44 02 PM"
src="https://github.com/user-attachments/assets/bf0db1d3-c32c-4b10-bf92-b4ac1b56d5c6"
/>

### Why

The test expectations for squiggly error counts were inverted between
the regular code block test and the payload code block test.

The regular code block test expected 1 error but got 0, while the
payload code block test expected 0 errors but should expect 1.

### How

Corrected the error count expectations to match actual Monaco editor
behavior:
- Regular code block (no semantic validation): expects 0 errors
- Payload code block (with type checking): expects 1 error for invalid
imports

---------

Co-authored-by: Alessio Gravili <github@gravili.net>

Author: PatrikKozak

test/lexical/collections/_LexicalFullyFeatured/e2e.spec.ts

@@ -196,20 +196,20 @@ describe('Lexical Fully Featured', () => {
   test('ensure code block can be created using client-side markdown shortcuts', async ({
     page,
   }) => {
-    await page.keyboard.type('```ts ')
+    await page.keyboard.type('```typescript ')
     const codeBlock = lexical.editor.locator('.LexicalEditorTheme__block-Code')
     await expect(codeBlock).toHaveCount(1)
     await expect(codeBlock).toBeVisible()
 
     await expect(codeBlock.locator('.monaco-editor')).toBeVisible()
     await expect(
       codeBlock.locator('.payload-richtext-code-block__language-selector-button'),
-    ).toHaveAttribute('data-selected-language', 'ts')
+    ).toHaveAttribute('data-selected-language', 'typescript')
 
     // Ensure it does not contain payload types
     await codeBlock.locator('.monaco-editor .view-line').first().click()
     await page.keyboard.type("import { APIError } from 'payload'")
-    await expect(codeBlock.locator('.monaco-editor .view-overlays .squiggly-error')).toHaveCount(1)
+    await expect(codeBlock.locator('.monaco-editor .view-overlays .squiggly-error')).toHaveCount(0)
   })
 
   test('ensure payload code block can be created using slash commands and it contains payload types', async ({
@@ -229,6 +229,10 @@ describe('Lexical Fully Featured', () => {
     await codeBlock.locator('.monaco-editor .view-line').first().click()
     await page.keyboard.type("import { APIError } from 'payload'")
     await expect(codeBlock.locator('.monaco-editor .view-overlays .squiggly-error')).toHaveCount(0)
+
+    await page.keyboard.press('Enter')
+    await page.keyboard.type("import { DoesNotExist } from 'payload'")
+    await expect(codeBlock.locator('.monaco-editor .view-overlays .squiggly-error')).toHaveCount(1)
   })
 
   test('copy pasting a inline block within range selection should not duplicate the inline block id', async ({