Arch Linux

Description: `ModuleNotFoundError: No module named 'pip._vendor.retrying'` on newly installed ArchLinux Server.


Additional info:
* package version(s): 20.3.4-4
* link to upstream bug report, if any: https://github.com/pypa/pip/issues/6261


Steps to reproduce:
Run `pacman -S python python-pip` followed by just `pip`.


Full error:
```
Traceback (most recent call last):
File "/usr/bin/pip", line 33, in <module>
sys.exit(load_entry_point('pip==20.3.4', 'console_scripts', 'pip')())
File "/usr/bin/pip", line 25, in importlib_load_entry_point
return next(matches).load()
File "/usr/lib/python3.10/importlib/metadata/__init__.py", line 162, in load
module = import_module(match.group('module'))
File "/usr/lib/python3.10/importlib/__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 883, in exec_module
File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
File "/usr/lib/python3.10/site-packages/pip/_internal/cli/main.py", line 10, in <module>
from pip._internal.cli.autocompletion import autocomplete
File "/usr/lib/python3.10/site-packages/pip/_internal/cli/autocompletion.py", line 9, in <module>
from pip._internal.cli.main_parser import create_main_parser
File "/usr/lib/python3.10/site-packages/pip/_internal/cli/main_parser.py", line 7, in <module>
from pip._internal.cli import cmdoptions
File "/usr/lib/python3.10/site-packages/pip/_internal/cli/cmdoptions.py", line 25, in <module>
from pip._internal.cli.progress_bars import BAR_TYPES
File "/usr/lib/python3.10/site-packages/pip/_internal/cli/progress_bars.py", line 12, in <module>
from pip._internal.utils.logging import get_indentation
File "/usr/lib/python3.10/site-packages/pip/_internal/utils/logging.py", line 18, in <module>
from pip._internal.utils.misc import ensure_dir
File "/usr/lib/python3.10/site-packages/pip/_internal/utils/misc.py", line 26, in <module>
from pip._vendor.retrying import retry # type: ignore
ModuleNotFoundError: No module named 'pip._vendor.retrying'
```