haskell.yml: remove useless steps: artifacts production

[smelc]

Changelog

- description: |
    haskell.yml: remove useless steps: artifacts production
# uncomment types applicable to the change:
  type:
  # - feature        # introduces a new feature
  # - breaking       # the API has changed in a breaking way
  # - compatible     # the API has changed but is non-breaking
  # - optimisation   # measurable performance improvements
  - refactoring    # QoL changes
  # - bugfix         # fixes a defect
  # - test           # fixes/modifies tests
  # - maintenance    # not directly related to the code
  # - release        # related to a new release preparation
  # - documentation  # change in code docs, haddocks...

Context

We have two steps in the CI that:

1. Builds an archive with the executables produced by the build
2. Save this archive as a GitHub artifact

But we have no executable produced during our build, so those steps are useless. You can see that in the last PR that was merged:

https://github.com/IntersectMBO/cardano-api/actions/runs/9500405626/job/26183389287?pr=448

Look at the considered steps, that mention they are useless:

How to trust this PR

• CI still passes
• It's only deletions

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• Self-reviewed the diff

[Jimbo4350]

💪