xfce4-notifyd: update to 0.9.4

0.9.4 (2024-02-09)
=====
- Clarify why the symbolic icons don't go in symbolic/status
- Fix icons directory names
- Fall back to monitor 0 if no primary monitor set
- Add a fallback for drawing the unread notification emblem
- Remove redundant icon embleming code
- Fix opacity on notification hover
- Translation Updates:
  Greek, Hungarian, Italian, Lithuanian, Occitan (post 1500)

(gutteridge)