python-setup: Fix pipenv (--keep-outdated deprecated)

Recently released pipenv removed support for `--keep-outdated` flag (see https://github.com/pypa/pipenv/blob/main/CHANGELOG.rst#pipenv-202379-2023-07-09)

Local testing showed that installation was fine without this 👍

python-setup/auto_install_packages.py

@@ -76,7 +76,7 @@ def install_packages_with_pipenv(has_lockfile):
         # In windows the default path were the deps are installed gets wiped out between steps,
         # so we have to set it up to a folder that will be kept
         os.environ['WORKON_HOME'] = os.path.join(os.environ['RUNNER_WORKSPACE'], 'virtualenvs')
-    lock_args = ['--keep-outdated', '--ignore-pipfile'] if has_lockfile else ['--skip-lock']
+    lock_args = ['--ignore-pipfile'] if has_lockfile else ['--skip-lock']
     try:
         _check_call(command + ['install'] + lock_args)
     except subprocess.CalledProcessError: