Log Message:
x11/xterm: update to 390

Patch #390 - 2024/02/19
 - improve typography of control-sequences page (patches by Branden Robinson).
 - amend UPSS change from patch #389, fixing a regression in VT100/VT220
   character sets.
 - modify ANSI conformance per ECMA-43 and DEC 070:
    - set ANSI conformance level to 3 for DEC levels 2 and up.
    - disable locking shifts in level 1, e.g., VT100.
    - disable single-shifts from G2/G3 in level 1.
    - use UPSS for G2/G3 in levels 2 and up.
 - modify invisible-character attribute to permit DECRQCRA to report a
   consistent checksum (report/testcase by Thomas Wolff).
 - align terminfo building blocks in terminfo to correspond to recent
   refactoring/trimming in ncurses.
 - set flag in regexec call for onNClicks to handle “^” anchor
   (patch by Matthew Martin).
 - add line-drawing data for the characters in DEC Technical which have no
   Unicode equivalents.
 - remove a special case in encode_scs which made xterm report Latin-1 when
   encoding is set to UTF-8, where ASCII is the selected character set.
   This fixes a regression in vttest for the DECRSPS cursor test.
 - correct values for Ps of DECAUPSS in ctlseqs.ms
   (report by James Holderness).
 - simplify/correct expression for checking Unicode non-characters
   (report by Thomas Wolff).
 - correct loop for trimming environment variables (report/patch by Casper Dik).
 - fixes for manpage formatting (Debian #1041809).
 - update config.guess, config.sub