Revert "[varLib.merger] only insert merged PairPosFormat1 subtable if at least one font has one"
Revert "[varLib.merger] only insert merged PairPosFormat1 subtable if at least one font has one"

This reverts commit d83c2fb2090fa58f94fdf32d1aa2d2d8665cec05.

This is wrong. We should insert if and only iff there's at least one of the
fonts with a Format1. Yours doesn't look at all fonts. Since this one is not a
bugfix but improvement, I'll fix it separately.

fonttools/fonttools,googlefonts/fonttools