[New Model] Devstral support (#6547)

Signed-off-by: Xinyuan Tong <justinning0323@outlook.com>

python/sglang/srt/hf_transformers_utils.py

@@ -203,6 +203,10 @@ def get_tokenizer(
             raise ValueError("Cannot use the fast tokenizer in slow tokenizer mode.")
         kwargs["use_fast"] = False
 
+    # TODO(Xinyuan): Remove this once we have a proper tokenizer for Devstral
+    if tokenizer_name == "mistralai/Devstral-Small-2505":
+        tokenizer_name = "mistralai/Mistral-Small-3.1-24B-Instruct-2503"
+
     is_gguf = check_gguf_file(tokenizer_name)
     if is_gguf:
         kwargs["gguf_file"] = tokenizer_name