refactor: remove module level global statement (#34)

The global statement is used to specify that the assignment to that name is an assignment to the variable in the global (module) scope, rather than in the local scope. At the module level, this statement is redundant because the local scope and global scope are the same. It is recommended to remove the `global` statement.

Co-authored-by: deepsource-autofix[bot] <62050782+deepsource-autofix[bot]@users.noreply.github.com>

src/plugins/waifu/__init__.py

@@ -260,7 +260,6 @@ async def check_divorce_rule(event):
 
 # 分手
 if waifu_cd_bye > -1:
-    global cd_bye
     cd_bye = {}
     bye = on_command(
         "离婚",