Remove openvino support in favor of external plugin (#15339)

Signed-off-by: Russell Bryant <rbryant@redhat.com>

setup.py

@@ -449,10 +449,6 @@ def _is_cpu() -> bool:
     return VLLM_TARGET_DEVICE == "cpu"
 
 
-def _is_openvino() -> bool:
-    return VLLM_TARGET_DEVICE == "openvino"
-
-
 def _is_xpu() -> bool:
     return VLLM_TARGET_DEVICE == "xpu"
 
@@ -572,8 +568,6 @@ def get_vllm_version() -> str:
         if gaudi_sw_version != MAIN_CUDA_VERSION:
             gaudi_sw_version = gaudi_sw_version.replace(".", "")[:3]
             version += f"{sep}gaudi{gaudi_sw_version}"
-    elif _is_openvino():
-        version += f"{sep}openvino"
     elif _is_tpu():
         version += f"{sep}tpu"
     elif _is_cpu():
@@ -623,8 +617,6 @@ def get_requirements() -> list[str]:
         requirements = _read_requirements("neuron.txt")
     elif _is_hpu():
         requirements = _read_requirements("hpu.txt")
-    elif _is_openvino():
-        requirements = _read_requirements("openvino.txt")
     elif _is_tpu():
         requirements = _read_requirements("tpu.txt")
     elif _is_cpu():
@@ -634,7 +626,7 @@ def get_requirements() -> list[str]:
     else:
         raise ValueError(
             "Unsupported platform, please use CUDA, ROCm, Neuron, HPU, "
-            "OpenVINO, or CPU.")
+            "or CPU.")
     return requirements