libXaw3d: update to 1.6.6.

This release fixes a failure to build with the upcoming gcc 14 compiler,
and drops code checks for a number of OS'es from the previous millenium
(none of which have actually been supported since the conversion from
imake to autoconf builds).

Alan Coopersmith (11):
      gitlab CI: add xz-utils to container for "make distcheck"
      Multisink.c: Clear -Werror=incompatible-pointer-types error
      unifdef NCR
      unifdef sony
      unifdef AIXV3
      unifdef __osf__
      unifdef __UNIXOS2__
      Remove unused sharedlib.c
      unifdef macII
      unifdef ISC
      libXaw3d 1.6.6

(wiz)