stylesheet: Add checked style for marked_days in calendar
When gtk made GtkCalendar widget-centric, marked days were flagged as CHECKED, but the css was never correctly added.
See: gtk@a6f9052c See: gtk!5399 (merged)
When gtk made GtkCalendar widget-centric, marked days were flagged as CHECKED, but the css was never correctly added.
See: gtk@a6f9052c See: gtk!5399 (merged)