Fix compatibility with text < 2.1

[hasufell]

@Bodigrim

[Bodigrim]

There are plenty of old releases, so perhaps it's easier just to restrict build-depends: text > 2.1 (instead of current text > 0.2.1 which is probably a typo).

As a Hackage trustee I made a few revisions to the existing releases of bytesmith, eliminating unbuildable configurations. (I used cabal-matrix to explore it, thanks @mniip)

[hasufell]

9.6.7 is still recommended in GHCup and ships with text-2.0.2