Remove unused packages

[philderbeast]

Fixes #9853. I am a bit frustrated that I've not been able fix or suppress the -Werror=unused-package with cabal-testsuite except with the following setting in project-cabal/ghc-options.config;

package cabal-testsuite
  ghc-options: -Wwarn=unused-packages

I tried adding similar ghc-options to cabal-testsuite:test:test-runtime-deps (the intentional source of unused package dependencies) but suppose project settings override package settings.

• Patches conform to the coding conventions.
• Is this a PR that fixes CI? If so, it will need to be backported to older cabal release branches (ask maintainers for directions).

[philderbeast]

@Mikolaj don't know what is going on with CI but the validate old ghc jobs are all failing with;

Run haskell-actions/setup@v2
/usr/bin/docker exec  9757b91719926d88402087692c8f087a5632be69e683d1466bd001285e16eb96 sh -c "cat /etc/*release | grep ^ID"
/__e/node20/bin/node: /lib/x86_64-linux-gnu/libm.so.6: version `GLIBC_2.27' not found (required by /__e/node20/bin/node)
/__e/node20/bin/node: /lib/x86_64-linux-gnu/libc.so.6: version `GLIBC_2.28' not found (required by /__e/node20/bin/node)
/__e/node20/bin/node: /lib/x86_64-linux-gnu/libc.so.6: version `GLIBC_2.25' not found (required by /__e/node20/bin/node)

[philderbeast]

I ran locally something close to Validate old ghcs 8.4.4 and found one unexpected pass;

$ ghc --version
The Glorious Glasgow Haskell Compilation System, version 8.8.4

$ sh validate.sh -j 24 -v -s build

$ sh validate.sh -j 24 -v --lib-only -s lib-suite-extras --extra-hc ghc-8.4.4
...
PackageTests/ForeignLibs/setup.test.hs     FAIL (unexpected success) (2.98s)
...
532 tests, 390 skipped, 1 unexpected passes, 0 unexpected fails.
UNEXPECTED OK: PackageTests/ForeignLibs/setup.test.hs
...

[philderbeast]

The Validate old ghcs problem is #9858.

[Mikolaj]

Thank you. Much needed Spring cleaning. :)

[philderbeast]

Label merge+no rebase is necessary when the pull request is from an organisation.