remove distutils

This patch removes the version check from __init__.py, which broke in Python
3.12 with the removal of distutils after being deprecated since Python 3.10. No
replacement test is introduced as dependency checks should be the
responsibility of pip.

nutils/__init__.py

@@ -1,12 +1,5 @@
 'Numerical Utilities for Finite Element Analysis'
 
-import sys
-import numpy
-from distutils.version import LooseVersion
-
-assert sys.version_info >= (3, 5)
-assert LooseVersion(numpy.version.version) >= LooseVersion('1.16'), 'nutils requires numpy 1.16 or higher, got {}'.format(numpy.version.version)
-
 __version__ = version = '8.3'
 version_name = 'idiyappam'
 long_version = ('{} "{}"' if version_name else '{}').format(version, version_name)