NEW YORK—In a very modest dwelling in Cork City, Ireland, two 30-somethng siblings wrestle with a long-standing problem: The problem lumbers noisily about upstairs. It is their old codger of a dad, getting more and more difficult by the day to care for. This is the gist of Kevin Barry’s “Autumn Royal,” the Irish Repertory Theatre’s first audience-present offering since the pandemic began. Timmy (John Keating) and his sister May (Maeve Higgins) are just about worn out after years of this stress. Should they continue to put their own lives on hold, or should they take some sort of action? May doesn’t seem very ambitious, but Timmy has been yearning for years to move to Australia, where he will surf to his heart’s content, marry some cute blonde, and work for some unnamed business. May points out that Timmy’s past try at surfing ended disastrously. The pair soon tires of …