Create a minimal derivation for linting tools

Created by: tomprince

Also, use flake8 plugins for reporting black and isort errors.

This creates a derivation with just the binaries needed for linting, which can then be included in an environment, and not have clashes with other derivations that have python libraries.

This is an alternative way of solving the shell.nix issue that #301 is solving, without the dependency interference.

Created by: codecov[bot]

Codecov Report

Merging #302 (bf92620) into main (ef54036d) will decrease coverage by 0.06%. The diff coverage is n/a.

@@            Coverage Diff             @@
##             main     #302      +/-   ##
==========================================
- Coverage   91.60%   91.53%   -0.07%     
==========================================
  Files          53       53              
  Lines        4751     4751              
  Branches      645      645              
==========================================
- Hits         4352     4349       -3     
- Misses        347      349       +2     
- Partials       52       53       +1     

Impacted Files	Coverage Δ
src/_zkapauthorizer/model.py	94.24% <0.00%> (-0.64%)
src/_zkapauthorizer/tests/test_client_resource.py	97.10% <0.00%> (-0.33%)

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update ef54036...bf92620. Read the comment docs.

Thanks. I took #301.