avoid duplicate validation in set_value

Co-authored-by: Sebastian Thiel <sebastian.thiel@icloud.com>

Author: codex

git/config.py

@@ -923,7 +923,7 @@ def set_value(self, section: str, option: str, value: Union[str, bytes, int, flo
         value_str = self._value_to_string_safe(value)
         if not self.has_section(section):
             self.add_section(section)
-        self.set(section, option, value_str)
+        super().set(section, option, value_str)
         return self
 
     @needs_values