Fails to parse elifs correctly

[TeofilC]

I'm seeing failures in CI from microcabal failing to parse elif expressions, eg:

    if impl(ghc < 9.14)
        build-depends: template-haskell
    elif impl(ghc)
        build-depends: template-haskell-lift >= 0.1 && <0.2

See: haskell/containers#1162

I can see that there is a commit adding support for elif expressions so I'm not sure why these are failing to parse.

[augustss]

Probably because the CI is pegged ho using a particular version of mhs. It's time to update that.