2. Update `GHCup.Version` module. `ghcupURL` must only be updated if we change the `GHCupInfo` type or the YAML representation of it. The version of the YAML represents the change increments. `ghcUpVer` is the current application version, read from `ghcup.cabal`.
4. Add/fix downloads in `ghcup-<ver>.yaml` (under `data/metadata`), then verify with `ghcup-gen check -f ghcup-<ver>.yaml` and possibly (example only) `ghcup-gen check-tarballs -f ghcup-<ver>.yaml -u 'ghc-8.10.7'`. Generally, new GHC/cabal/stack/hls versions are only added to the latest yaml file. New GHCup versions are added to all (great care must be taken here to not break the parser... e.g. ARM platforms don't parse in all older formats).