Missing *.map files in distribution packages.

[mhozza]

Seems like css map files are missing in the distribution packages on pypi.
This causes issues with whitenoise which attempts to hash them to create unique versioned static files.

Post-processing 'rest_framework/css/bootstrap-theme.min.css' failed!
#0 0.634 
#0 0.634 Traceback (most recent call last):
#0 0.634   File "/web/manage.py", line 18, in <module>
#0 0.634     execute_from_command_line(sys.argv)
#0 0.634   File "/usr/local/lib/python3.10/site-packages/django/core/management/__init__.py", line 446, in execute_from_command_line
#0 0.634     utility.execute()
#0 0.634   File "/usr/local/lib/python3.10/site-packages/django/core/management/__init__.py", line 440, in execute
#0 0.634     self.fetch_command(subcommand).run_from_argv(self.argv)
#0 0.634   File "/usr/local/lib/python3.10/site-packages/django/core/management/base.py", line 402, in run_from_argv
#0 0.635     self.execute(*args, **cmd_options)
#0 0.635   File "/usr/local/lib/python3.10/site-packages/django/core/management/base.py", line 448, in execute
#0 0.635     output = self.handle(*args, **options)
#0 0.635   File "/usr/local/lib/python3.10/site-packages/django/contrib/staticfiles/management/commands/collectstatic.py", line 209, in handle
#0 0.635     collected = self.collect()
#0 0.635   File "/usr/local/lib/python3.10/site-packages/django/contrib/staticfiles/management/commands/collectstatic.py", line 154, in collect
#0 0.635     raise processed
#0 0.635 whitenoise.storage.MissingFileError: The file 'rest_framework/css/bootstrap-theme.min.css.map' could not be found with <whitenoise.storage.CompressedManifestStaticFilesStorage object at 0x7f8367373d30>.
#0 0.635 
#0 0.635 The CSS file 'rest_framework/css/bootstrap-theme.min.css' references a file which could not be found:
#0 0.635   rest_framework/css/bootstrap-theme.min.css.map
#0 0.635 
#0 0.635 Please check the URL references in this CSS file, particularly any
#0 0.635 relative paths which might be pointing to the wrong location.