shell.nix: Fix compatibility with Nix >= 2.10.0 on x86_64-darwin

[sigprof]

Description

The poetry package from the used Nixpkgs snapshot is no longer buildable when using the official binary releases of Nix >= 2.10.0 on x86_64-darwin due to a regex compatibility issue (NixOS/nix#4758). The failure looks like:

error: invalid regular expression '^.*?(egg|tar|tar.bz2|tar.gz|tar.lz|tar.lzma|tar.xz|tbz|tgz|tlz|txz|whl|zip)'
       at /nix/store/gm4rp1786ligd81v2qz420nkrwy0r50k-nixpkgs-src/pkgs/development/tools/poetry2nix/poetry2nix/mk-poetry-dep.nix:42:42:
           41|           matchesVersion = fname: builtins.match ("^.*" + builtins.replaceStrings [ "." ] [ "\\." ] version + ".*$") fname != null;
           42|           hasSupportedExtension = fname: builtins.match supportedRegex fname != null;
             |                                          ^
           43|           isCompatibleEgg = fname: ! lib.strings.hasSuffix ".egg" fname || lib.strings.hasSuffix "py${python.pythonVersion}.egg" fname;

In addition, all poetry version earlier than 1.1.14 became effectively non-functional after a breaking change of the PyPI JSON API (python-poetry/poetry#5973) — they generate broken poetry.lock files without any hash values, therefore the old version of poetry that was added to the Nix shell environment became useless anyway.

Updating the poetry package to the most recent stable release (1.1.14 at the moment) without bumping nixpkgs is not trivial:

• Just adding poetry = ">=1.1.14" to pyproject.toml does not work due to dependency version conflicts with other modules.
• Although poetry2nix exports a poetry package, it makes that package available only as a flake output (it could be possible to import overlay.nix from there directly, but that is not documented; this would also require changing the arguments added in Allow overriding Niv's sources in shell.nix #16602 — poetry2nix ? pkgs.callPackage (import sources.poetry2nix) { } would no longer be sufficient).

Given those facts, looks like the only way to fix the problem without major changes is to remove the poetry package from the Nix shell environment. This should not cause any problems for QMK users, because the poetry tool is not needed to compile the QMK firmware — it may be needed only if someone wants to update the Nix shell environment itself, and in that case something like nix run github:NixOS/nixpkgs/nixos-unstable#poetry could be used for now.

I don't actually have any Apple hardware to test this on, but the failure could be observed on the macos-* machines provided by GitHub (e.g., https://github.com/sigprof/qmk-nix-support/actions/runs/2666127722 — failed tests are for the master code without this change). The failure started to happen after the Nix 2.10.0 release a couple of days ago (cachix/install-nix-action installs the latest stable Nix release by default); Nix 2.10.1 did not change anything.

Cc: @purcell @AstridYu @andresilva

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• Keymap/layout/userspace (addition or update)
• Documentation

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).

[purcell]

Makes sense to me, thanks