Dakota keeps plugging away at the studio during Friday afternoon. She sporting the same grey t-shirt we saw Kristen wear earlier this week. Photos found at Gossip Girls. A casting company called Hollywood OS has been holding an open casting call for extras in The Runaways. Interested parties should report to the Hollywood OS office at 3108 W. Magnolia Blvd in Burbank between 1pm and 4pm Mond…