Docs: drop Python 2 support

The kernel build system as a whole is dropping support for Python 2, so we
should do the same.  The effects are rather small, especially considering
that much of the deleted code was not doing anything under any version of
Python anyway.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/sphinx/maintainers_include.py

@@ -61,8 +61,6 @@ class MaintainersInclude(Include):
         field_content = ""
 
         for line in open(path):
-            if sys.version_info.major == 2:
-                line = unicode(line, 'utf-8')
             # Have we reached the end of the preformatted Descriptions text?
             if descriptions and line.startswith('Maintainers'):
                 descriptions = False