ci: add arm64 attestation

Do the very same thing that we do on amd64 and add attestation

Signed-off-by: Zvonko Kaiser <zkaiser@nvidia.com>

.github/workflows/build-kata-static-tarball-arm64.yaml

@@ -24,6 +24,11 @@ on:
 jobs:
   build-asset:
     runs-on: ubuntu-22.04-arm
+    permissions:
+      contents: read
+      packages: write
+      id-token: write
+      attestations: write
     strategy:
       matrix:
         asset:
@@ -38,6 +43,8 @@ jobs:
           - qemu
           - stratovirt
           - virtiofsd
+    env:
+      PERFORM_ATTESTATION: ${{ matrix.asset == 'agent' && inputs.push-to-registry == 'yes' && 'yes' || 'no' }}
     steps:
       - name: Login to Kata Containers quay.io
         if: ${{ inputs.push-to-registry == 'yes' }}
@@ -74,6 +81,34 @@ jobs:
           TARGET_BRANCH: ${{ inputs.target-branch }}
           RELEASE: ${{ inputs.stage == 'release' && 'yes' || 'no' }}
 
+      - name: Parse OCI image name and digest
+        id: parse-oci-segments
+        if: ${{ env.PERFORM_ATTESTATION == 'yes' }}
+        run: |
+          oci_image="$(<"build/${{ matrix.asset }}-oci-image")"
+          echo "oci-name=${oci_image%@*}" >> "$GITHUB_OUTPUT"
+          echo "oci-digest=${oci_image#*@}" >> "$GITHUB_OUTPUT"
+
+      - uses: oras-project/setup-oras@v1
+        if: ${{ env.PERFORM_ATTESTATION == 'yes' }}
+        with:
+          version: "1.2.0"
+
+      # for pushing attestations to the registry
+      - uses: docker/login-action@v3
+        if: ${{ env.PERFORM_ATTESTATION == 'yes' }}
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - uses: actions/attest-build-provenance@v1
+        if: ${{ env.PERFORM_ATTESTATION == 'yes' }}
+        with:
+          subject-name: ${{ steps.parse-oci-segments.outputs.oci-name }}
+          subject-digest: ${{ steps.parse-oci-segments.outputs.oci-digest }}
+          push-to-registry: true
+
       - name: store-artifact ${{ matrix.asset }}
         uses: actions/upload-artifact@v4
         with: