drop pyversion & is_python3 checking

We're committed to Python 3 at this point, so purge all the
is_python3 related dynamic checks.

Bug: https://crbug.com/gerrit/10418
Change-Id: I4c8b405d6de359b8b83223c9f4b9c8ffa18ea1a2
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/292383
Reviewed-by: Chris Mcdonald <cjmcdonald@google.com>
Tested-by: Mike Frysinger <vapier@google.com>
diff --git a/hooks.py b/hooks.py
index f805de6..67c21a2 100644
--- a/hooks.py
+++ b/hooks.py
@@ -19,20 +19,11 @@
 import subprocess
 import sys
 import traceback
+import urllib.parse
 
 from error import HookError
 from git_refs import HEAD
 
-from pyversion import is_python3
-if is_python3():
-  import urllib.parse
-else:
-  import imp
-  import urlparse
-  urllib = imp.new_module('urllib')
-  urllib.parse = urlparse
-  input = raw_input  # noqa: F821
-
 
 class RepoHook(object):
   """A RepoHook contains information about a script to run as a hook.