STAGE

Going, Going: Lloyd Richards, dean of the Yale School of Drama and artistic director of the Yale Repertory Theatre since 1979, will leave both posts in June, 1991. The announcement was made Sunday by Benno C. Schmidt Jr., president of Yale University, who added that a faculty committee has been appointed to search for a successor. Richards, whose staging of August Wilson’s “The Piano Lesson” is at the Doolittle Theatre in Hollywood, brought Wilson’s work to national prominence while at Yale.