Veteran comedy actor Wayne Federman is joining the cast of HBO's Silicon Valley for its seven-episode final season, Collider has exclusively learned. Silicon Valley is set to return in October, though production had been delayed until summer to accommodate showrunner Alec Berg, who also serves as the showrunner of HBO’s Barry. The Emmy-winning series stars Thomas Middleditch, Kumail Nanjiani, Martin Starr, Zach Woods, Josh Brener, Jimmy O. Yang, Amanda Crew, Suzanne Cryer and Matt Ross. Federman will be playing a character from someone's past whose identity is being kept under wraps. The humorous character actor …