ci: GHA basic format & pre-commit (#2309)

diff --git a/tests/test_buffers.py b/tests/test_buffers.py
index bf7aaed..e264311 100644
--- a/tests/test_buffers.py
+++ b/tests/test_buffers.py
@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 import io
 import struct
 import sys