Use sharejs doc type in Storybook stories (#33565)

GitOrigin-RevId: a2bf64d3ce376dd05e740796e8f1ea74913ed8f0

services/web/frontend/stories/source-editor/source-editor.stories.tsx

@@ -331,7 +331,7 @@ const mockDoc = (content: string, changes: Array<Record<string, any>> = []) => {
       // Do nothing
     },
     getType: () => {
-      return 'history-ot'
+      return 'sharejs-text-ot'
     },
     on: () => {
       // Do nothing