[pkg] don't run 2to3 in setup.py

We can now run directly on python3 (3.3+, and at least as far as running
tests).

Closes #265740

setup.py

@@ -38,12 +38,7 @@ except ImportError:
     from distutils.command import install_lib
     USE_SETUPTOOLS = 0
 
-try:
-    # python3
-    from distutils.command.build_py import build_py_2to3 as build_py
-except ImportError:
-    # python2.x
-    from distutils.command.build_py import build_py
+from distutils.command.build_py import build_py
 
 sys.modules.pop('__pkginfo__', None)
 # import optional features
@@ -137,14 +132,6 @@ class MyBuildPy(build_py):
                 dest = join(basedir, directory)
                 shutil.rmtree(dest, ignore_errors=True)
                 shutil.copytree(directory, dest)
-                if sys.version_info >= (3, 0):
-                    # process manually python file in include_dirs (test data)
-                    from distutils.util import run_2to3
-                    # brackets are NOT optional here for py3k compat
-                    print('running 2to3 on', dest)
-                    run_2to3([dest])
-
-
 
 
 def install(**kwargs):