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

diff --git a/tools/libsize.py b/tools/libsize.py
index 5dcb8b0..50f88bd 100644
--- a/tools/libsize.py
+++ b/tools/libsize.py
@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 from __future__ import print_function, division
 import os
 import sys
@@ -35,4 +36,3 @@
 
 with open(save, 'w') as sf:
     sf.write(str(libsize))
-