Katie Couric didn’t seem too worried about getting up at the crack of dawn to host “GMA” this week. The fill-in host was seen partying at Top of the Standard till 11:30 p.m. after a Cinema Society premiere of HBO’s hipster series, “Girls.” Executive producer Judd Apatow joked at the SVA Theater screening about another anchor, saying, “Thank you for coming to the most uncomfortable night of Brian Williams’ life!” (Williams’ daughter, Allison, stars in a particularly racy scene in the series.) Show creator Lena Dunham tweeted at guest and her former baby sitter Zac Posen, “You were the best babysitter . . . you did my hair ‘like a newscaster’ and made me a frayed leather skirt.”