Comparing BaseLLM class instead of LLM (#3120)

* Compaing BaseLLM class instead of LLM

* Fixed test cases

* Fixed Linting Issues

* removed last line

---------

Co-authored-by: Lucas Gomide <lucaslg200@gmail.com>

src/crewai/tasks/llm_guardrail.py

@@ -1,10 +1,9 @@
-from typing import Any, Optional, Tuple
+from typing import Any, Tuple
 
 from pydantic import BaseModel, Field
 
 from crewai.agent import Agent, LiteAgentOutput
-from crewai.llm import LLM
-from crewai.task import Task
+from crewai.llm import BaseLLM
 from crewai.tasks.task_output import TaskOutput
 
 
@@ -32,11 +31,11 @@ class LLMGuardrail:
     def __init__(
         self,
         description: str,
-        llm: LLM,
+        llm: BaseLLM,
     ):
         self.description = description
 
-        self.llm: LLM = llm
+        self.llm: BaseLLM = llm
 
     def _validate_output(self, task_output: TaskOutput) -> LiteAgentOutput:
         agent = Agent(