devel/notcurses: Update to 2.0.8

Several bugfixes, enhancements and some new features
from version 2.0.4 to 2.0.8

Changelog: https://github.com/dankamongmen/notcurses/blob/master/NEWS.md

PR: 251449
Submitted by: Nick Black <nickblack@linux.com>
Approved by: arrowd, tcberner (mentors, implicit)