AD: Remove the legacy check from ad_get_account_domain_posix_check request
    
    Previously, the POSIX attribute presence check was run as part of the ID
    request, so it was necessary to also run the check as part of the
    get-domain-for-ID request.
    
    Since moving the POSIX check to being a part of the subdomain provider,
    this is no longer needed as the subdomain provider disables the GC
    support on its own if required. Therefore we can just remove the POSIX
    check from the get-domain-for-ID request.
    
    Related:
    https://pagure.io/SSSD/sssd/issue/3755
    
    Reviewed-by: Pavel Březina <pbrezina@redhat.com>