Updated type hint for timeout model config option

Co-authored-by: Nathan Habib <30601243+NathanHB@users.noreply.github.com>

Author: rolshoven

src/lighteval/models/endpoints/litellm_model.py

@@ -130,7 +130,7 @@ class LiteLLMModelConfig(ModelConfig):
     api_max_retry: int = 8
     api_retry_sleep: float = 1.0
     api_retry_multiplier: float = 2.0
-    timeout: float = None
+    timeout: float | None = None
 
 
 class LiteLLMClient(LightevalModel):