Lorenze/tracing-improvements-cleanup (#3291)

* feat: add tracing support to Crew and Flow classes

- Introduced a new `tracing` optional field in both the `Crew` and `Flow` classes to enable tracing functionality.
- Updated the initialization logic to conditionally set up the `TraceCollectionListener` based on the `tracing` flag or the `CREWAI_TRACING_ENABLED` environment variable.
- Removed the obsolete `interfaces.py` file related to tracing.
- Enhanced the `TraceCollectionListener` to accept a `tracing` parameter and adjusted its internal logic accordingly.
- Added tests to verify the correct setup of the trace listener when tracing is enabled.

This change improves the observability of the crew execution process and allows for better debugging and performance monitoring.

* fix flow name

* refactor: replace _send_batch method with finalize_batch calls in TraceCollectionListener

- Updated the TraceCollectionListener to use the batch_manager's finalize_batch method instead of the deprecated _send_batch method for handling trace events.
- This change improves the clarity of the code and ensures that batch finalization is consistently managed through the batch manager.
- Removed the obsolete _send_batch method to streamline the listener's functionality.

* removed comments

* refactor: enhance tracing functionality by introducing utility for tracing checks

- Added a new utility function `is_tracing_enabled` to streamline the logic for checking if tracing is enabled based on the `CREWAI_TRACING_ENABLED` environment variable.
- Updated the `Crew` and `Flow` classes to utilize this utility for improved readability and maintainability.
- Refactored the `TraceCollectionListener` to simplify tracing checks and ensure consistent behavior across components.
- Introduced a new module for tracing utilities to encapsulate related functions, enhancing code organization.

* refactor: remove unused imports from crew and flow modules

- Removed unnecessary `os` imports from both `crew.py` and `flow.py` files to enhance code cleanliness and maintainability.

src/crewai/flow/flow.py

@@ -2,7 +2,6 @@ import asyncio
 import copy
 import inspect
 import logging
-import os
 from typing import (
     Any,
     Callable,
@@ -36,6 +35,7 @@ from crewai.utilities.events.flow_events import (
 from crewai.utilities.events.listeners.tracing.trace_listener import (
     TraceCollectionListener,
 )
+from crewai.utilities.events.listeners.tracing.utils import is_tracing_enabled
 from crewai.utilities.printer import Printer
 
 logger = logging.getLogger(__name__)
@@ -441,6 +441,7 @@ class Flow(Generic[T], metaclass=FlowMeta):
     _router_paths: Dict[str, List[str]] = {}
     initial_state: Union[Type[T], T, None] = None
     name: Optional[str] = None
+    tracing: Optional[bool] = False
 
     def __class_getitem__(cls: Type["Flow"], item: Type[T]) -> Type["Flow"]:
         class _FlowGeneric(cls):  # type: ignore
@@ -452,6 +453,7 @@ class Flow(Generic[T], metaclass=FlowMeta):
     def __init__(
         self,
         persistence: Optional[FlowPersistence] = None,
+        tracing: Optional[bool] = False,
         **kwargs: Any,
     ) -> None:
         """Initialize a new Flow instance.
@@ -469,8 +471,9 @@ class Flow(Generic[T], metaclass=FlowMeta):
 
         # Initialize state with initial values
         self._state = self._create_initial_state()
-        if os.getenv("CREWAI_TRACING_ENABLED", "false").lower() == "true":
-            trace_listener = TraceCollectionListener()
+        self.tracing = tracing
+        if is_tracing_enabled() or tracing:
+            trace_listener = TraceCollectionListener(tracing=tracing)
             trace_listener.setup_listeners(crewai_event_bus)
         # Apply any additional kwargs
         if kwargs: