python39Packages.asttokens: unbreak

[rmcgibbo]

Motivation for this change

Fixes https://hydra.nixos.org/build/139259720

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

[r-rmcgibbo]

Result of nixpkgs-review pr 117609 at b618d8d run on aarch64-linux 1

3 packages failed to build:

• python39Packages.executing
• python39Packages.icecream
• python39Packages.stack-data

3 packages skipped due to time constraints:

• vyper (python38Packages.vyper)
• python39Packages.vyper
• thonny

5 packages built successfully:

• python38Packages.asttokens
• python38Packages.executing
• python38Packages.icecream
• python38Packages.stack-data
• python39Packages.asttokens

Note that build failures may predate this PR, and could be nondeterministic or hardware dependent.
Please exercise your independent judgement.

[rmcgibbo]

The build failures look pre-existing to me, although they were probably shadowed because of this package failing to build.