Fix lint issues in asyncio_utils.py

- Remove trailing whitespace from blank lines
- Remove unused loop variable

Co-Authored-By: João <joao@crewai.com>

src/crewai/utilities/asyncio_utils.py

@@ -1,37 +1,37 @@
 """Utilities for handling asyncio operations safely across different contexts."""
 
 import asyncio
-from typing import Any, Coroutine
+from collections.abc import Coroutine
+from typing import Any
 
 
 def run_coroutine_sync(coro: Coroutine) -> Any:
     """
     Run a coroutine synchronously, handling both cases where an event loop
     is already running and where it's not.
-    
+
     This is useful when you need to run async code from sync code, but you're
     not sure if you're already in an async context (e.g., when using asyncio.to_thread).
-    
+
     Args:
         coro: The coroutine to run
-        
+
     Returns:
         The result of the coroutine
-        
+
     Raises:
         Any exception raised by the coroutine
     """
     try:
-        loop = asyncio.get_running_loop()
+        asyncio.get_running_loop()
     except RuntimeError:
         return asyncio.run(coro)
     else:
-        import concurrent.futures
         import threading
-        
+
         result = None
         exception = None
-        
+
         def run_in_new_loop():
             nonlocal result, exception
             try:
@@ -43,11 +43,11 @@ def run_coroutine_sync(coro: Coroutine) -> Any:
                     new_loop.close()
             except Exception as e:
                 exception = e
-        
+
         thread = threading.Thread(target=run_in_new_loop)
         thread.start()
         thread.join()
-        
+
         if exception:
             raise exception
         return result