[Frontend] Require flag for loading text and image embeds (#27204)

Signed-off-by: DarkLight1337 <tlleungac@connect.ust.hk>
Co-authored-by: DarkLight1337 <tlleungac@connect.ust.hk>

tests/models/multimodal/generation/test_common.py

@@ -109,8 +109,7 @@ VLM_TEST_SETTINGS = {
                 limit_mm_per_prompt={"image": 4},
             )
         ],
-        # TODO: Revert to "auto" when CPU backend can use torch > 2.6
-        dtype="bfloat16" if current_platform.is_cpu() else "auto",
+        vllm_runner_kwargs={"enable_mm_embeds": True},
         marks=[pytest.mark.core_model, pytest.mark.cpu_model],
     ),
     "qwen2_5_vl": VLMTestInfo(