Make load_config keyword arguments keyword-only

Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

RELEASE_NOTES.md

@@ -26,6 +26,8 @@
         + The class is now immutable.
         + The constructor now accepts only keyword arguments.
 
+    * `load_config()`: the `base_schema` argument is now keyword-only.
+
 ## New Features
 
 - `LoggingConfigUpdatingActor`

src/frequenz/sdk/config/_util.py

@@ -32,6 +32,7 @@ def load_config(
     cls: type[DataclassT],
     config: Mapping[str, Any],
     /,
+    *,
     base_schema: type[Schema] | None = None,
     **marshmallow_load_kwargs: Any,
 ) -> DataclassT: