python3Packages.testpath: fix tests on Darwin

[austinbutler]

Motivation for this change

Works around jupyter/testpath#24.

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 21.11 Release Notes (or backporting 21.05 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

[austinbutler]

@SuperSandro2000 mind taking another look?

[SuperSandro2000]

@ofborg build python39Packages.testpath

[SuperSandro2000]

python3Minimal fails on staging so it is quite hard to validate if this change works or not.

[austinbutler]

python3Minimal fails on staging so it is quite hard to validate if this change works or not.

Yes I just found that as well locally when testing unrelated things. Seems like a patch fails to apply.

[austinbutler]

I think it may be that both #146477 and #145752 were merged in staging, but I don't think Python 3.9.9 needs the bpo-44689 patch.

[austinbutler]

#148519 likely fixed that problem.

@ofborg build python39Packages.testpath