The resurgence of interest in the work of playwright A.R. Gurney will continue in the fall with a revival of Sylvia starring competing Tony Award nominees Annaleigh Ashford (You Can’t Take It With You, Kinky Boots) and Julie White (Airline Highway). They’re two of the most gifted and in-demand comedians working today. This comes on the heels of Gurney’s continuing residency at the invaluable Signature Theatre Company and last season’s starry round-robin revival of Love Let…