pylint: drop disable=import-error for py3 modules

We had to use these on modules that were only in Python 3, but
since we're using a python3 linter now, we can drop these.

BUG=None
TEST=`cros lint --py3` still works

Change-Id: Ia7765c987b23558893184b8ba2383827b5934cb8
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2658931
Tested-by: Mike Frysinger <vapier@chromium.org>
Auto-Submit: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Chris McDonald <cjmcdonald@chromium.org>
Reviewed-by: Chris McDonald <cjmcdonald@chromium.org>
diff --git a/licensing/licenses_lib.py b/licensing/licenses_lib.py
index 4f42d26..16762eb 100644
--- a/licensing/licenses_lib.py
+++ b/licensing/licenses_lib.py
@@ -12,7 +12,7 @@
 from __future__ import print_function
 
 import codecs
-import html  # pylint: disable=import-error
+import html
 import os
 import re
 from typing import List, Optional
diff --git a/test/portage_testables.py b/test/portage_testables.py
index 998f66d..73d6436 100644
--- a/test/portage_testables.py
+++ b/test/portage_testables.py
@@ -10,7 +10,7 @@
 
 import itertools
 import os
-import pathlib  # pylint: disable=import-error
+import pathlib
 from typing import Dict, Iterable, Tuple, Union
 
 from chromite.lib import constants