Don't depend on pkg_resources

[ataylor32]

Expected Behavior

I should be able to run a command like python manage.py shell without any errors.

Current Behavior

[ERROR] management_commands File "/var/www/example.com/manage.py", line 33: Management command error: manage.py shell
Traceback (most recent call last):
  File "/var/www/example.com/manage.py", line 31, in main
    execute_from_command_line(sys.argv)
  File "/var/www/example.com/venv/lib/python3.12/site-packages/django/core/management/__init__.py", line 442, in execute_from_command_line
    utility.execute()
  File "/var/www/example.com/venv/lib/python3.12/site-packages/django/core/management/__init__.py", line 416, in execute
    django.setup()
  File "/var/www/example.com/venv/lib/python3.12/site-packages/django/__init__.py", line 24, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/var/www/example.com/venv/lib/python3.12/site-packages/django/apps/registry.py", line 91, in populate
    app_config = AppConfig.create(entry)
                 ^^^^^^^^^^^^^^^^^^^^^^^
  File "/var/www/example.com/venv/lib/python3.12/site-packages/django/apps/config.py", line 193, in create
    import_module(entry)
  File "/usr/lib/python3.12/importlib/__init__.py", line 90, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen importlib._bootstrap>", line 1387, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1360, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1331, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 935, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 995, in exec_module
  File "<frozen importlib._bootstrap>", line 488, in _call_with_frames_removed
  File "/var/www/example.com/venv/lib/python3.12/site-packages/user_sessions/__init__.py", line 1, in <module>
    from pkg_resources import DistributionNotFound, get_distribution
ModuleNotFoundError: No module named 'pkg_resources'

Your Environment

• Python version: 3.12.3
• Django version: 4.2.11
• django-user-sessions version: 2.0.0

Relevant: python/cpython#95299

[WhyNotHugo]

pkg_resources is used to read the current package version.

We should probably write the version into a file at build time instead with something like:

[build-system]
requires = ["setuptools>=45", "wheel", "setuptools_scm>=6.2"]

[tool.setuptools_scm]
write_to = "user_sessions/version.py"
version_scheme = "no-guess-dev"

init.py can then use:

from . import version

__version__ = version.version