By Dan Marsh Mikel Arteta is relaxed at the prospect of watching title rivals Liverpool and Manchester City collide on Sunday after Arsenal returned to the Premier League summit. The Gunners knew that victory over Brentford at the Emirates would send them top of the league with the teams above them playing each other on Sunday. And although they left it late, Arsenal got the job done against the Bees, beating them 2-1. Arteta’s men are now one point clear of Liverpool and two clear of the reigning champions ahead of their grudge match at Anfield. And the Spaniard is ready to sit back and watch…