ncurses 6.3 - patch 20211120

+ add dim, ecma+strikeout to st-0.6 -TD
+ deallocate the tparm cache when del_curterm is called for the last
  allocated TERMINAL structure (report/testcase by Bram Moolenaar,
  cf: 20200531).
+ modify test-package to more closely conform to Debian multi-arch.
+ if the --with-pkg-config-libdir option is not given, use
  ${libdir}/pkgconfig as a default (prompted by discussion with Ross
  Burton).