github: Disable ARM64 worker

This machine is no longer available.

Signed-off-by: Rob Bradford <rbradford@rivosinc.com>

.github/workflows/integration-arm64.yaml

@@ -1,54 +0,0 @@
-name: Cloud Hypervisor Tests (ARM64)
-on: [pull_request, merge_group]
-concurrency:
-  group: ${{ github.workflow }}-${{ github.ref }}
-  cancel-in-progress: true
-
-jobs:
-  build:
-    timeout-minutes: 60
-    name: Tests (ARM64)
-    runs-on: focal-arm64
-    steps:
-      - name: Fix workspace permissions
-        run: sudo chown -R github-runner:github-runner ${GITHUB_WORKSPACE}
-      - name: Code checkout
-        uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
-      - name: Run unit tests (musl)
-        run: scripts/dev_cli.sh tests --unit --libc musl
-      - name: Load openvswitch module
-        run: sudo modprobe openvswitch
-      - name: Run integration tests (musl)
-        timeout-minutes: 30
-        run: scripts/dev_cli.sh tests --integration --libc musl
-      - name: Install Azure CLI
-        if: ${{ github.event_name != 'pull_request' }}
-        run: |
-          sudo apt install -y ca-certificates curl apt-transport-https lsb-release gnupg
-          curl -sL https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/microsoft.gpg > /dev/null
-          echo "deb [arch=arm64] https://packages.microsoft.com/repos/azure-cli/ focal main" | sudo tee /etc/apt/sources.list.d/azure-cli.list
-          sudo apt update
-          sudo apt install -y azure-cli
-      - name: Download Windows image
-        if: ${{ github.event_name != 'pull_request' }}
-        shell: bash
-        run: |
-          IMG_BASENAME=windows-11-iot-enterprise-aarch64.raw
-          IMG_PATH=$HOME/workloads/$IMG_BASENAME
-          IMG_GZ_PATH=$HOME/workloads/$IMG_BASENAME.gz
-          IMG_GZ_BLOB_NAME=windows-11-iot-enterprise-aarch64-9-min.raw.gz
-          cp "scripts/$IMG_BASENAME.sha1" "$HOME/workloads/"
-          pushd "$HOME/workloads"
-          if sha1sum "$IMG_BASENAME.sha1" --check; then
-              exit
-          fi
-          popd
-          mkdir -p "$HOME/workloads"
-          az storage blob download --container-name private-images --file "$IMG_GZ_PATH" --name "$IMG_GZ_BLOB_NAME" --connection-string "${{ secrets.CH_PRIVATE_IMAGES }}"
-          gzip -d $IMG_GZ_PATH
-      - name: Run Windows guest integration tests
-        if: ${{ github.event_name != 'pull_request' }}
-        timeout-minutes: 30
-        run: scripts/dev_cli.sh tests --integration-windows --libc musl