chore(callbacks): add deprecation notice to get_trace_id and get_trac…

…e_url (langfuse#414)

langfuse/utils/base_callback_handler.py

@@ -96,9 +96,23 @@ def __init__(
             )
 
     def get_trace_id(self):
+        """
+        This method is deprecated and will be removed in a future version as it is not concurrency-safe.
+        Please refer to the [documentation](https://langfuse.com/docs/integrations/langchain/get-started#interoperability) on how to use interop with the Langfuse SDK to get the id of a trace.
+
+        Returns:
+            The ID of the current/last trace or None if no trace is available.
+        """
         return self.trace.id if self.trace else None
 
     def get_trace_url(self):
+        """
+        This method is deprecated and will be removed in a future version as it is not concurrency-safe.
+        Please refer to the [documentation](https://langfuse.com/docs/tracing/url) for more information.
+
+        Returns:
+            The URL of the current/last trace or None if no trace is available.
+        """
         return self.trace.get_trace_url() if self.trace else None
 
     def flush(self):