refactor FeatureTemplateLibrary implementation

Author: nmaarnio

arho_feature_template/core/models.py

@@ -80,14 +80,9 @@ def from_config_file(
                             description=feature_data.get("description"),
                             regulation_groups=[
                                 group
-                                for group in [
-                                    cls.find_matching_group_config(group_name, regulation_group_libraries)
-                                    for group_name in feature_data.get("regulation_groups")
-                                ]
-                                if group
-                            ]
-                            if feature_data.get("regulation_groups")
-                            else [],
+                                for group_name in feature_data.get("regulation_groups", [])
+                                if (group := cls.find_matching_group_config(group_name, regulation_group_libraries))
+                            ],
                             plan_id=None,
                             id_=None,
                         )