fix: use abspath for symlinks in collate step; reduce CI to 2 models
- notification_service.py: os.symlink(os.path.abspath(d), ...) to fix
broken relative symlinks when collate_ci_source_deps.py reads artifact dirs
- self-scheduled-caller.yml: reduce subdirs to ['models/bert', 'models/clip']
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>