Run actionlint in CI + make it available in dev shell

[smelc]

Changelog

- description: |
    Run actionlint in CI
# 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

API version of the same feature in CLI. I thought I had added it, but no 😅

How to trust this PR

• This is the same setup as in CLI.
• Look at the new pipeline run on this PR: https://github.com/IntersectMBO/cardano-api/actions/runs/9096723061/job/25002809274?pr=536

Checklist

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