sayaka: update to 3.4.4.

pkgsrc changes:
- remove leftover (should be done on 3.3.0) from Makefile
- explicitly specify required versions of vala and glib2 per README.md

Upstream changes:

* 3.4.4 (2020/05/01)
  fix unexpected exit on receiving SIGWINCH on Linux.
  adjust drawing of contiguous retweets.
  extend timeout to determine SIXEL support.
  change behavior of --token option.
  misc modifications around logs.

(tsutsui)