`cabal check` doesn't detect using invalid version syntax for spec versions prior to 1.24

This already caused 4 incidents in the package index (see https://github.com/haskell-infra/hackage-trustees/issues/128)

@phadej found the culprit at 6b3457de66772d958fd5fe96066b08e93d0fb0c7 which relaxed the `Version` parser to accommodate parsing `pkg-config` output (which imho deserves its own version parsing anyway), and as an overlooked side-effect also relaxed the parsing of the cabal format.