fix: enhance PlusAPI and TraceBatchManager with timeout handling and graceful failure logging (#3416)

* Added timeout parameters to PlusAPI trace event methods for improved reliability.
* Updated TraceBatchManager to handle None responses gracefully, logging warnings instead of errors.
* Improved logging messages to provide clearer context during trace batch initialization and event sending failures.

src/crewai/cli/shared/token_manager.py

@@ -56,6 +56,8 @@ class TokenManager:
         :return: The access token if valid and not expired, otherwise None.
         """
         encrypted_data = self.read_secure_file(self.file_path)
+        if encrypted_data is None:
+            return None
 
         decrypted_data = self.fernet.decrypt(encrypted_data)  # type: ignore
         data = json.loads(decrypted_data)