By Emma Baccellieri Seattle’s newest upgrade to its pitching rotation will take the team farther into October than just ending its 20-year playoff drought this season. If the Mariners’ front office does not speak about the team’s playoff drought in explicit terms very often, well, it’s only fair—the streak predates any of them. (When Seattle last made the postseason in 2001, current president of baseball operations Jerry Dipoto was 33, only just done with his playing career.) Seattle’s drought has not been about the failures or poor planning or bad luck of any one regime. It’s bigger. But it’s…