Merge branch 'support-azure-ad-users-again'

As of the upgrade to v3.6.2, I can no longer open any MinTTY windows: It
errors out with the message "Error: Could not fork child process: There
are no available terminals (-1)".

This symptom was also described on the Cygwin mailing list:
https://inbox.sourceware.org/cygwin/CAL148o6i=r+G=cEQzs5e+KmMt07FxJHhMnoNnquhM0JJuyrwtA@mail.gmail.com/#t

I've bisected the problem down to 48e7d63 (Cygwin:
fetch_account_from_windows: skip LookupAccountSid for SIDs known to
fail, 2025-04-10), which prevents my AzureAD user account (the SID
begins with `S-1-12-1-`) from being handled correctly.

This PR is a (minimally) partial revert of that commit to resolve this
problem.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

winsup/cygwin/uinfo.cc

@@ -2002,10 +2002,6 @@ pwdgrp::fetch_account_from_windows (fetch_user_arg_t &arg, cyg_ldap *pldap)
       if (sid_id_auth (sid) == 5 /* SECURITY_NT_AUTHORITY */
 	  && sid_sub_auth (sid, 0) == SECURITY_APPPOOL_ID_BASE_RID)
 	break;
-      /* AzureAD SIDs */
-      if (sid_id_auth (sid) == 12 /* AzureAD ID */
-	  && sid_sub_auth (sid, 0) == 1 /* Azure ID base RID */)
-	break;
       /* Samba user/group SIDs */
       if (sid_id_auth (sid) == 22)
 	break;