drop python 3.6 support

python 3.6 reached end of life on 2021-12-23

pre_commit/languages/system.py

@@ -1,5 +1,6 @@
+from __future__ import annotations
+
 from typing import Sequence
-from typing import Tuple
 
 from pre_commit.hook import Hook
 from pre_commit.languages import helpers
@@ -15,5 +16,5 @@ def run_hook(
         hook: Hook,
         file_args: Sequence[str],
         color: bool,
-) -> Tuple[int, bytes]:
+) -> tuple[int, bytes]:
     return helpers.run_xargs(hook, hook.cmd, file_args, color=color)