changed totalTime to be a getter for preptime + cooktime

lib/services/providers/recipe_provider.dart

@@ -66,13 +66,6 @@ class RecipeProvider extends ChangeNotifier {
     }
   }
 
-  void updateTotalTime(Duration totalTime, {bool silent = false}) {
-    _recipe = _recipe.copyWith(totalTime: totalTime);
-    if (!silent) {
-      notifyListeners();
-    }
-  }
-
   void updateKeywords(List<String> keywords, {bool silent = false}) {
     _recipe = _recipe.copyWith(keywords: keywords);
     if (!silent) {