GHC release process: Add checks for packaging issues
I propose that, as a part of the pre-release checks, package candidates and haddocks for the GHC-maintained libraries be uploaded to Hackage. Ideally, this would already be done for release candidates or even beta and alpha releases, so interested users can check out the docs. These checks should also be performed for minor releases that include updates of GHC-maintained libraries.
Motivation: In recent GHC releases, there have been several issues with the upload of the GHC-maintained libraries and their haddocks, e.g. #19811 (closed), #20698 (closed), #21304 (closed), #21337 (closed), #21339. I hope that catching such issues before the actual release will improve the quality of the GHC-maintained libraries on Hackage.