tools: Remove unused imports.

Signed-off-by: Anders Kaseorg <andersk@mit.edu>

tools/linter_lib/pep8.py

@@ -1,8 +1,6 @@
 from __future__ import print_function
 from __future__ import absolute_import
 
-import subprocess
-
 from zulint.linters import run_pycodestyle
 
 from typing import List

tools/linter_lib/pyflakes.py

@@ -6,7 +6,7 @@ import subprocess
 
 from zulint.printer import print_err, colors
 
-from typing import Any, Dict, List
+from typing import List
 
 suppress_patterns = [
     (b'', b'imported but unused'),