Brooke Shields finally explained why she attended Tom Cruise and Katie Holmes’ 2006 wedding. After the Blue Lagoon actress, 58, and the Top Gun star infamously feuded over Shields’ use of antidepressants to treat her postpartum depression, Shields revealed why she ended up being present at the former power couple’s special day after Cruise apologized for his comments about her. “Of course, I was going to say yes to that,” the Wonderful Town actress noted in a recent interview of the lavish ceremony in Italy. “I was like, ‘Yes. I will — as long as I’m not the something old!'” Shields admitted i…