The food is about the only thing worth going to Safeco for these days.It’s been a godawful year for major league baseball fans in the Pacific Northwest. The Mariners have been out of the pennant hunt since shortly after the season’s first pitch and rank among the worst teams in baseball, having just fired their manager. None of their overhyped offseason acquisitions have panned out for squat, and all-time favorite Ken Griffey Jr. retired near midseason after it became evident that his fortysomething bat couldn’t catch up with big-league fastballs anymore.But at the concession stand, the club’s effort has been all-star caliber. A revamped menu at the beginning of the season (and the menu was already relatively dynamic to begin with) introduced dishes like poutine to Safeco Field regulars, and then the club filled a gaping hole in its liquor lineup by permitting Edgar Martinez to sell his mezcal at select sites around the stadium.What to do for an encore? Go gluten-free!Mind you, total freedom from the evil protein will only occur in one section (347) for one day (August 31). But the M’s are slashing prices ($11 for the special tickets instead of the usual $20) to get fans who’d normally shy away from ballpark fare into the preordained section, where gluten-free hot dog buns and Redbridge beer made from sorghum will be available.