Arch Linux

Description:

On a fresh Archlinux install, installing the qtile package is not enough as it is missing a dependency on python-setuptools.

Additional info:
* package version(s): 0.18.0-2

Steps to reproduce:

- Remove any python-* packages from the system (or start on a fresh arch install).
- pacman -S qtile
- Launch qtile and the following error will occur:


```
Traceback (most recent call last):
File "/usr/lib/python3.9/site-packages/libqtile/scripts/main.py", line 9, in <module>
import pkg_resources
ModuleNotFoundError: No module named 'pkg_resources'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/usr/bin/qtile", line 33, in <module>
sys.exit(load_entry_point('qtile==0.18.1.dev0+g8e7ecc0a.d20210719', 'console_scripts', 'qtile')())
File "/usr/bin/qtile", line 25, in importlib_load_entry_point
return next(matches).load()
File "/usr/lib/python3.9/importlib/metadata.py", line 77, in load
module = import_module(match.group('module'))
File "/usr/lib/python3.9/importlib/__init__.py", line 127, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 1030, in _gcd_import
File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
File "<frozen importlib._bootstrap>", line 986, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 680, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 850, in exec_module
File "<frozen importlib._bootstrap>", line 228, in _call_with_frames_removed
File "/usr/lib/python3.9/site-packages/libqtile/scripts/main.py", line 11, in <module>
except (pkg_resources.DistributionNotFound, ImportError):
NameError: name 'pkg_resources' is not defined
```