Wham City’s favorite son Dan Deacon will be joined by District dance provocateur Gavin Holland for the next After Hours party at the Hirshhorn Museum and Sculpture Garden. The party on November 7 will be the last After Hours party of the year and possibly the most uproarious yet. Deacon commands a mass following who is very willing to dance at his implore, while DJ Holland’s Nouveau Riche — called the best D.C. dance night…