wasi-nn: update openvino crate, use external CI action (#4383)

* ci: replace OpenVINO installer action

To test wasi-nn, we currently use an OpenVINO backend. The Wasmtime CI
must install OpenVINO using a custom GitHub action. This CI action has
not been updated in some time and in the meantime OpenVINO (and the
OpenVINO crates) have released several new versions.
https://github.com/abrown/install-openvino-action is an external action
that we plan to keep up to date with the latest releases. This change
replaces the current CI action with that one.

* wasi-nn: upgrade openvino dependency to v0.4.1

This eliminates a `lazy_static` dependency and changes a few parameters
to pass by reference. Importantly, it enables support for the latest
versions of OpenVINO (v2022.*) in wasi-nn.

* ci: update wasi-nn script to source correct env script

* ci: really use the correct path for the env script

Also, clarify which directory OpenVINO is installed in (the symlink may
not be present).

ci/run-wasi-nn-example.sh

@@ -20,10 +20,10 @@ fi
 
 # Inform the environment of OpenVINO library locations. Then we use OPENVINO_INSTALL_DIR below to avoid building all of
 # OpenVINO from source (quite slow).
-source /opt/intel/openvino_2021/bin/setupvars.sh
+source /opt/intel/openvino_2022/setupvars.sh
 
 # Build Wasmtime with wasi-nn enabled; we attempt this first to avoid extra work if the build fails.
-OPENVINO_INSTALL_DIR=/opt/intel/openvino cargo build -p wasmtime-cli --features wasi-nn
+OPENVINO_INSTALL_DIR=/opt/intel/openvino_2022 cargo build -p wasmtime-cli --features wasi-nn
 
 # Download all necessary test fixtures to the temporary directory.
 wget --no-clobber $FIXTURE/mobilenet.bin --output-document=$TMP_DIR/model.bin