Let users choose the OpenVINO device plugins for onnxruntime-ep-openvino

<details><summary>Claude's draft</summary>

Drop the run dependencies on the OpenVINO device plugins (intel-cpu,
intel-gpu, intel-npu, auto, hetero, auto-batch) to keep the package
slim. Users install the plugins for the devices they want, e.g.
`libopenvino-intel-npu-plugin`. The EP still depends on libopenvino
through its run_exports, and every plugin pins libopenvino exactly, so
plugins installed later match the version the EP was built against.

The test runs on the OpenVINO CPU device, so libopenvino-intel-cpu-plugin
moves to the test requirements.

Resume this Claude session:
```
cd /home/mark/git/feedstock
claude --resume fdaba65c-5a43-4f26-a32f-d49b747fdbd7
```
</details>

Claude-Session: https://claude.ai/code/session_01R9WZp6UVaiXYyC2hWTNWZY

Author: hmaarrfk

recipe/recipe.yaml

@@ -452,14 +452,6 @@ outputs:
           - libopenvino-dev
       run:
         - python
-        - libopenvino-intel-cpu-plugin
-        - libopenvino-intel-gpu-plugin
-        - if: linux
-          then:
-            - libopenvino-intel-npu-plugin
-        - libopenvino-auto-plugin
-        - libopenvino-hetero-plugin
-        - libopenvino-auto-batch-plugin
       run_constraints:
         - onnxruntime ${{ version }}.*
         - onnxruntime-novec ${{ version }}.*
@@ -476,6 +468,7 @@ outputs:
           run:
             - ${{ pin_subpackage('onnxruntime' ~ suffix, exact=True) }}
             - onnx
+            - libopenvino-intel-cpu-plugin
         files:
           recipe:
             - test_ep_openvino.py