Update diffcalc action to checkout the correct upstream branch
Update diffcalc action to checkout the correct upstream branch

NeoAdonis/osu,peppy/osu-new,smoogipoo/osu,smoogipoo/osu,peppy/osu,NeoAdonis/osu,ppy/osu,smoogipooo/osu,ppy/osu,peppy/osu,ppy/osu,peppy/osu,NeoAdonis/osu,smoogipoo/osu