replace deprecated distutils

distutils will get removed in python 3.12. It is usage is now replaced
by sysconfig. For py2 version code stays in specfile.

https://docs.python.org/3/whatsnew/3.10.html#distutils-deprecated

Related: https://pagure.io/koji/issue/3514

devtools/get_site_packages.py

@@ -0,0 +1,8 @@
+# prints site-packages path for use in Makefiles
+
+try:
+    from distutils.sysconfig import get_python_lib
+    print(get_python_lib())
+except ImportError:
+    import sysconfig
+    print(sysconfig.get_path('purelib', 'rpm_prefix'))