feat: define families dictionary for candidate classifiers in _build_candidate_families function

app/training/train_classifier.py

@@ -370,6 +370,7 @@ def _class_ratio(y: np.ndarray) -> float:
 
 
 def _build_candidate_families(y: np.ndarray) -> dict[str, list[Any]]:
+    families: dict[str, list[Any]] = {
         "Logistic Regression": [
             LogisticRegression(
                 C=value,