CHICAGO — Steppenwolf Theatre Company, one of Chicago’s most storied arts institutions and long a crucial part of the city’s identity, said Thursday that it was laying off 12% of its staff, effectively immediately. Thirteen current employees have been let go, with seven open positions eliminated. Steppenwolf executive director Brooke Flanagan said in an interview that the theater’s subscription base had fallen from about 10,000 subscribers in pre-pandemic 2019 to about 6,000 today. She also said that single-ticket sales were down 31%, even as expenses were up 19% over the same term. (Steppenwo...