drop custom encoding warning as min python bump to 3.10

DanielYang59 · DanielYang59 · commit 0aeb65763f09 · 2024-12-12T18:55:32.000+08:00
diff --git a/src/monty/io.py b/src/monty/io.py
@@ -22,9 +22,6 @@
     from typing import IO, Any, Iterator, Union
 
 
-class EncodingWarning(Warning): ...  # Added in Python 3.10
-
-
 def zopen(
     filename: Union[str, Path],
     /,
