refactor(editor): move transcription block model to ai (#12010)

<!-- This is an auto-generated comment: release notes by coderabbit.ai -->

## Summary by CodeRabbit

- **Refactor**
	- Updated and reorganized import paths for transcription block models and types to improve module structure and maintainability.
- **Chores**
	- Removed deprecated transcription block schema and related exports from core libraries.
	- Registered transcription block schema directly within the workspace schema for improved schema management.
- **Bug Fixes**
	- Ensured consistent registration and availability of transcription block features across relevant modules.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

blocksuite/affine/all/src/extensions/migrating-store.ts

@@ -8,10 +8,7 @@ import {
   type StoreExtensionContext,
   StoreExtensionProvider,
 } from '@blocksuite/affine-ext-loader';
-import {
-  RootBlockSchemaExtension,
-  TranscriptionBlockSchemaExtension,
-} from '@blocksuite/affine-model';
+import { RootBlockSchemaExtension } from '@blocksuite/affine-model';
 import {
   HtmlAdapterFactoryExtension,
   ImageProxyService,
@@ -69,7 +66,6 @@ function getNotionHtmlAdapterExtensions(): ExtensionType[] {
 
 const MigratingStoreExtensions: ExtensionType[] = [
   RootBlockSchemaExtension,
-  TranscriptionBlockSchemaExtension,
 
   BlockSelectionExtension,
   TextSelectionExtension,