[fix]: remove data type hardcoding from gptoss model implementation (#23807)

Signed-off-by: Nikhil Gupta <nikhil.gupta2@arm.com>

vllm/model_executor/models/gpt_oss.py

@@ -76,7 +76,6 @@ class OAIAttention(nn.Module):
 
         self.sinks = torch.nn.Parameter(
             torch.empty(config.num_attention_heads // tp_size,
-                        dtype=torch.bfloat16,
                         requires_grad=False))
 
         self.q_size = self.num_attention_heads * self.head_dim // tp_size
@@ -145,8 +144,7 @@ class MLPBlock(torch.nn.Module):
         self.experts_per_token = config.num_experts_per_tok
         self.world_size = dist.get_world_size() if dist.is_initialized() else 1
         self.router = torch.nn.Linear(config.hidden_size,
-                                      config.num_local_experts,
-                                      dtype=torch.bfloat16)
+                                      config.num_local_experts)
         assert config.intermediate_size % self.world_size == 0
         self.experts = FusedMoE(num_experts=config.num_local_experts,
                                 top_k=config.num_experts_per_tok,