fix: apps/annotation missing 1 required positional argument: 'end_user'

[quicksandznzn]

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3. Use the correct syntax to link this PR: Fixes apps/annotation missing 1 required positional argument: 'end_user' #20427 , Fixes createAppAnnotation api error #20409

Summary

this pr #20240 remove validate_app_token attribute fetch_user_arg=FetchUserArg(fetch_from=WhereisUserArg.JSON)
resulting in null end_user

end_user: EndUseris not in use ,remove it to fix bug

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Before	After

Checklist

• This change requires a documentation update, included: Dify Document
• I understand that this PR may be closed in case there was no previous discussion or issues. (This doesn't apply to typos!)
• I've added a test for each change that was introduced, and I tried as much as possible to make a single atomic change.
• I've updated the documentation accordingly.
• I ran dev/reformat(backend) and cd web && npx lint-staged(frontend) to appease the lint gods