Restoring validation functionality after #383 turns out to not work f…

…or Python 3.11

paperqa/llms.py

@@ -6,6 +6,7 @@
 from collections.abc import AsyncIterable, Awaitable, Callable, Iterable, Sequence
 from enum import StrEnum
 from inspect import signature
+from sys import version_info
 from typing import Any
 
 import numpy as np
@@ -390,11 +391,13 @@ def maybe_set_config_attribute(cls, data: dict[str, Any]) -> dict[str, Any]:
                 "router_kwargs": {"num_retries": 3, "retry_after": 5},
             }
         # we only support one "model name" for now, here we validate
-        _DeploymentTypedDictValidator.validate_python(data["config"]["model_list"])
-        if (
-            "config" in data
-            and len({m["model_name"] for m in data["config"]["model_list"]}) > 1
-        ):
+        model_list = data["config"]["model_list"]
+        if version_info >= (3, 12):
+            _DeploymentTypedDictValidator.validate_python(model_list)
+        elif not isinstance(model_list, list):
+            # Work around https://github.com/BerriAI/litellm/issues/5664
+            raise TypeError(f"model_list must be a list, not a {type(model_list)}.")
+        if "config" in data and len({m["model_name"] for m in model_list}) > 1:
             raise ValueError("Only one model name per router is supported for now.")
         return data