[Bugfix] Fix isinstance check for tensor types in _load_prompt_embeds to use dtype comparison (#21612)

Signed-off-by: Alexandre Juan <a.juan@netheos.net>

vllm/entrypoints/openai/serving_engine.py

@@ -957,9 +957,11 @@ class OpenAIServing:
         def _load_and_validate_embed(embed: bytes) -> EmbedsPrompt:
             tensor = torch.load(io.BytesIO(base64.b64decode(embed)),
                                 weights_only=True)
-            assert isinstance(
-                tensor,
-                (torch.FloatTensor, torch.BFloat16Tensor, torch.HalfTensor))
+            assert isinstance(tensor, torch.Tensor) and tensor.dtype in (
+                torch.float32,
+                torch.bfloat16,
+                torch.float16,
+            )
             if tensor.dim() > 2:
                 tensor = tensor.squeeze(0)
                 assert tensor.dim() == 2