fix(editor): add code block clipboard extension (#11731)

Close [BS-3109](https://linear.app/affine-design/issue/BS-3109/code-block-不支援-markdown-語法)

blocksuite/affine/blocks/code/src/code-block-spec.ts

@@ -8,6 +8,7 @@ import type { ExtensionType } from '@blocksuite/store';
 import { literal, unsafeStatic } from 'lit/static-html.js';
 
 import { CodeBlockAdapterExtensions } from './adapters/extension.js';
+import { getCodeClipboardExtensions } from './clipboard/index.js';
 import {
   CodeBlockInlineManagerExtension,
   CodeBlockUnitSpecExtension,
@@ -33,4 +34,5 @@ export const CodeBlockSpec: ExtensionType[] = [
   CodeBlockAdapterExtensions,
   SlashMenuConfigExtension('affine:code', codeSlashMenuConfig),
   CodeKeymapExtension,
+  ...getCodeClipboardExtensions(),
 ].flat();