Use base64-bytestring instead of base64
base64 on ghc 8.6.5 on arm produces incorrect output, ultimately because of https://gitlab.haskell.org/ghc/ghc/-/issues/20338
base64 on ghc 8.6.5 on arm produces incorrect output, ultimately because of https://gitlab.haskell.org/ghc/ghc/-/issues/20338