Fix task name error

src/deepeval/deepeval_task_manager.py

@@ -15,7 +15,7 @@ class Task(Enum):
 class DeepEvalTaskManager:
     def __init__(self, model_name, tasks: List[str]):
         self.model_name = model_name
-        self.available_tasks = {task.name: getattr(Task, task.name).value for task in Task}
+        self.available_tasks = {task.name: getattr(self, task.value) for task in Task}
         self.tasks_to_run = self.validate_tasks(tasks)
 
     def validate_tasks(self, user_tasks):
@@ -33,8 +33,6 @@ class DeepEvalTaskManager:
         results = {}
         for task_name, task_method in self.tasks_to_run.items():
             task_enum = getattr(Task, task_name)
-
-            # Get the value of the enum member
             task_value = task_enum.value
             results[task_value] = task_method()  # Call the stored method reference