[gpt-oss] Add gpt-oss bf16 support

vllm/transformers_utils/chat_templates/template_chatml.jinja

@@ -0,0 +1,10 @@
+{%- for message in messages -%}
+    {{- '<|im_start|>' + message['role'] + '\n' + message['content'] -}}
+    {%- if (loop.last and add_generation_prompt) or not loop.last -%}
+        {{- '<|im_end|>' + '\n' -}}
+    {%- endif -%}
+{%- endfor -%}
+
+{%- if add_generation_prompt and messages[-1]['role'] != 'assistant' -%}
+    {{- '<|im_start|>assistant\n' -}}
+{%- endif -%}