Disable wasi-nn CI tests due to breakage (404'ing package repository). (#5028)

In #5023 we are seeing a failing CI job (see [1]); after four attempted
restarts, it 404's each time when trying to download OpenVino from the
Intel apt mirrors.

This PR temporarily removes the wasi-nn CI job from our CI configuration
so that we have green CI and can merge other work.

[1] https://github.com/bytecodealliance/wasmtime/actions/runs/3200861896/jobs/5228903240

.github/workflows/main.yml

@@ -342,21 +342,6 @@ jobs:
       env:
         RUST_BACKTRACE: 1
 
-  # Build and test the wasi-nn module.
-  test_wasi_nn:
-    name: Test wasi-nn module
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-        with:
-          submodules: true
-      - uses: ./.github/actions/install-rust
-      - run: rustup target add wasm32-wasi
-      - uses: abrown/install-openvino-action@v3
-      - run: ./ci/run-wasi-nn-example.sh
-        env:
-          RUST_BACKTRACE: 1
-
   # Build and test the wasi-crypto module.
   test_wasi_crypto:
     name: Test wasi-crypto module