Matthew Pickering authored May 05, 2022 and Marge Bot committed May 16, 2022

This adds a CI job (hackage-doc-tarball) which generates the necessary
tarballs for uploading libraries and documentation to hackage. The
release script knows to download this folder and the upload script will
also upload the release to hackage as part of the release.

The `ghc_upload_libs` script is moved from ghc-utils into .gitlab/ghc_upload_libs

There are two modes, preparation and upload.

* The `prepare` mode takes a link to a bindist and creates a folder containing the
  source and doc tarballs ready to upload to hackage.
* The `upload` mode takes the folder created by prepare and performs the upload to
  hackage.

Fixes #21493

Related to #21512