Add separate devShell for pre-commit

[Lucsanszky]

Description

Resolves #4231

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• New tests are added if needed and existing tests are updated
• When applicable, versions are updated in .cabal and CHANGELOG.md files according to the
  versioning process.
• The version bounds in .cabal files for all affected packages are updated. If you change the bounds in a cabal file, that package itself must have a version increase. (See RELEASING.md)
• All visible changes are prepended to the latest section of a CHANGELOG.md for the affected packages. New section is never added with the code changes. (See RELEASING.md)
• Code is formatted with fourmolu (use scripts/fourmolize.sh)
• Cabal files are formatted (use scripts/cabal-format.sh)
• hie.yaml has been updated (use scripts/gen-hie.sh)
• Self-reviewed the diff

[teodanciu]

Looks good to me, just a question about a snippet that I'm not sure whether is useful to keep or is part of the previous solution.
I think this solution is elegant and simpler, and this is witnessed by the simplifications in the instructions on enabling/disabling it.

[lehins]

Much better 🙂
Thank you