x11-wm/picom: Update 12.2 → 12.3

Changelog:
 Improvements
  - Extend workaround for missing hardware accelerated convolution to
    more drivers
 Bug fixes
  - Fix memory corruption that can happen when handling window property
    changes
  - Fix force-win-blend having no effect
  - Fix shadow being rendered incorrectly in xrender backend
https://github.com/yshui/picom/releases/tag/v12.3

PR:	282083
MFH:	2024Q4