Nicola Coughlan revealed she’s taking a step back from her role as Penelope Featherington in the forthcoming fifth season of “Bridgerton.” “It’s bittersweet,” the actress, 39, told E! News in an interview published Tuesday. “I feel like, God, I had such an epic run,” she continued. “I think that’s part of the beauty of that world is it keeps reinventing itself. Every season being a new story — it takes on a different guise.” Coughlan’s character was also the original Lady Whistledown, the secret author behind Regency London’s gossip pamphlet. Under the pen name, Featherington anonymously wrote about the ongoing events and secret affairs…