Remove telemetry and tracing dependencies from Task and Flow classes

- Remove telemetry-related imports and private attributes from Task class
- Remove `_telemetry` attribute from Flow class
- Update event handling to emit events without direct telemetry tracking
- Simplify task and flow execution by removing explicit telemetry spans
- Move telemetry-related event handling to EventListener

src/crewai/utilities/events/task_events.py

@@ -1,5 +1,4 @@
 from typing import Any, Optional
-
 from crewai.utilities.events.crew_events import CrewEvent
 
 
@@ -8,7 +7,6 @@ class TaskStartedEvent(CrewEvent):
 
     type: str = "task_started"
     context: Optional[str]
-    model_config = {"arbitrary_types_allowed": True}
 
 
 
@@ -18,12 +16,11 @@ class TaskCompletedEvent(CrewEvent):
     output: Any
     type: str = "task_completed"
 
-    model_config = {"arbitrary_types_allowed": True}
 
 
 class TaskFailedEvent(CrewEvent):
     """Event emitted when a task fails"""
 
-    task: Any
     error: str
     type: str = "task_failed"
+