fix: example issue (#2114)

Co-authored-by: Shubham Naik <shub@memgpt.ai>

letta/schemas/letta_base.py

@@ -63,7 +63,7 @@ def _id_regex_pattern(cls, prefix: str):
     @classmethod
     def _id_example(cls, prefix: str):
         """generates an example id for a given prefix"""
-        return [prefix + "-123e4567-e89b-12d3-a456-426614174000"]
+        return f"{prefix}-123e4567-e89b-12d3-a456-426614174000"
 
     @classmethod
     def _id_description(cls, prefix: str):