LOS ANGELES &#8212 Nonwriting staff members of “The Tonight Show with Jay Leno” became the latest casualties of the four-week Hollywood writers strike when they were laid off Friday. NBC confirmed the layoffs at the show without providing further details. The show went into reruns when the strike began on Nov. 5, and Leno honored the picket lines. NBC had been covering the salaries of the nonwriting staffers. Conan O’Brien has promised to cover the salaries of about 75 nonstriking “Late Night” staffers next week.