ghcup metadata includes extraneous dlOutput fields
ghcup can apparently infer the output name of an artifact from its URL.
Consequently, we should only include the dlOutput
field when it would
differ from the filename of dlUri
, as requested in https://github.com/haskell/ghcup-metadata/pull/186/files#diff-b7aa200da91425001d95ee963dc2b97e33c87f584d916569c69fa20b49795887.