Recognise SetupHooks.hs

[ffaf1]

Closes #11349
cabal check now recognises SetupHooks.hs as a valid setup script.

• Patches conform to the coding conventions.
• Any changes that could be relevant to users have been recorded in the changelog.
  • Is the change significant? If so, remember to add significance: significant in the changelog file.
• The documentation has been updated, if necessary.
• Manual QA notes have been included.
• Tests have been added. (Ask for help if you don’t know how to write them! Ask for an exemption if tests are too complex for too little coverage!)

QA NOTES

Download the repro in #11349, run cabal check.

[ffaf1]

Does this need backport? I think so, since it influences Hackage behaviour.

[Mikolaj]

+1