Bug 1604360 - [python] Fix ./mach python --ipython, r=mars

We recently updated the version of pip we use, and it no longer supports
--use-wheels.

Differential Revision: https://phabricator.services.mozilla.com/D57404

--HG--
extra : moz-landing-system : lando

python/mach_commands.py

@@ -77,7 +77,7 @@ class MachCommands(MachCommandBase):
                 if not no_virtualenv:
                     # Use `_run_pip` directly rather than `install_pip_package` to bypass
                     # `req.check_if_exists()` which may detect a system installed ipython.
-                    self.virtualenv_manager._run_pip(['install', '--use-wheel', 'ipython'])
+                    self.virtualenv_manager._run_pip(['install', 'ipython'])
                     python_path = which('ipython', path=bindir)
 
                 if not python_path: