Log Message:
misc/plan9port: update to latest snapshot.

Bring package in sync with most recent upstream commit (20240110).

Noteworthy changes:

* mntgen: import mntgen(4) from Plan 9
* ramfs: fixed bg in erealloc handling
* 9l: refactor the warning-silencing mechanics to match that of 9c
* page: fix viewing of graphics
* acme: have Dump save both low and high DPI fontnames
* libframe: Match the color of tick
* libdraw: fix subfont scaling
* libregexp: allow up to 127 captured subexpressions in one regexp
* plumber: increase NMATCHSUBEXP up to 100
* libregexp: allow up to 128 character classes in one regexp
* plumber: use strtoul to parse subexpression match variable
  substitutions
* plumber: increase NMATCHSUBEXP up to libregexp's NSUBEXP
* plumber: allow multi-digit subexpression match variable substitutions
* plumber: parametrize the number of stored match pattern subexpressions
* devdraw: Fix mouse wheel scrolling in 1-tick increments on macOS