wasi-nn: update openvino-rs to 0.6.0

[Iceber]

Openvino releases after 2023 no longer include the plugins.xml file, and openvino-rs 0.6.0 is compatible with it.
related issue: openvinotoolkit/openvino#17971

If you are using openvino-rs 0.5, you will get the following error when running openvino 2023:

 wasmtime run --dir $TMP_DIR::fixture -S nn,nn-graph=openvino::$TMP_DIR  $TMP_DIR/wasi-nn-example-named.wasm
Error: Failed while accessing backend

Caused by:
    0: library loading error
    1: cannot find path to XML plugin configuration (see https://github.com/intel/openvino-rs/blob/main/crates/openvino-finder)