python3.pkgs.httpie: add pip as a test dependency

[tjni]

Description of changes

This is needed once we remove pip from the ambient environment (which will happen when switching to build to build Python packages), or else we get mysterious test errors like:

_______________________ test_plugins_installation[True] ________________________

httpie_plugins_success = <function httpie_plugins_success.<locals>.runner at 0x7ffff1df8550>
interface = Interface(path=PosixPath('/build/pytest-of-nixbld/pytest-0/test_plugins_installation_True0/interface'), environment=<M...out': <tempfile._TemporaryFileWrapper object at 0x7ffff1deee90>,
 'stdout_encoding': 'utf-8',
 'stdout_isatty': True}>)
dummy_plugin = Plugin(interface=Interface(path=PosixPath('/build/pytest-of-nixbld/pytest-0/test_plugins_installation_True0/interface'...ue}>), name='httpie-270ea5c7', version='1.0.0', entry_points=[EntryPoint(name='test', group='httpie.plugins.auth.v1')])
cli_mode = True

    @pytest.mark.requires_installation
    @pytest.mark.parametrize('cli_mode', [True, False])
    def test_plugins_installation(httpie_plugins_success, interface, dummy_plugin, cli_mode):
>       lines = httpie_plugins_success('install', dummy_plugin.path, cli_mode=cli_mode)

tests/test_plugins_cli.py:10: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

cli_mode = True
args = ('install', PosixPath('/build/pytest-of-nixbld/pytest-0/test_plugins_installation_True0/interface/httpie-270ea5c7'))
response = 'Installing /build/pytest-of-nixbld/pytest-0/test_plugins_installation_True0/interface/httpie-270ea5c7...\n'

    def runner(*args, cli_mode: bool = True):
        response = httpie_plugins(*args, cli_mode=True)
>       assert response.exit_status == ExitStatus.SUCCESS
E       AssertionError

tests/utils/plugins_cli.py:233: AssertionError

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 rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 23.11 Release Notes (or backporting 23.05 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.

[tjni]

@ofborg build python310Packages.httpie python311Packages.httpie

[fabaff]

Result of nixpkgs-review pr 250256 run on x86_64-linux 1

10 packages built:

• http-prompt
• http-prompt.dist
• httpie (python310Packages.httpie)
• httpie.dist (python310Packages.httpie.dist)
• python310Packages.httpie-ntlm
• python310Packages.httpie-ntlm.dist
• python311Packages.httpie
• python311Packages.httpie-ntlm
• python311Packages.httpie-ntlm.dist
• python311Packages.httpie.dist

[fabaff]

Change looks good to me.