fix: add icon for code block (#10924)

Fixes #10923

<img width="422" alt="Screenshot 2025-03-16 at 1 44 51 AM"
src="https://github.com/user-attachments/assets/e8b638ce-0082-486a-92c0-f362dcf25f98"
/>

Co-authored-by: Weiko <corentin@twenty.com>

packages/twenty-front/src/modules/activities/blocks/utils/getSlashMenu.ts

@@ -1,5 +1,6 @@
 import { getDefaultReactSlashMenuItems } from '@blocknote/react';
 import {
+  IconCode,
   IconComponent,
   IconFile,
   IconH1,
@@ -27,6 +28,7 @@ const Icons: Record<string, IconComponent> = {
   'Numbered List': IconListNumbers,
   'Bullet List': IconList,
   'Check List': IconListCheck,
+  'Code Block': IconCode,
   Paragraph: IconPilcrow,
   Table: IconTable,
   Image: IconPhoto,