Do not upload artifacts for rpi3 (#3139)

We are not building raw images for it so the build dir is empty

Signed-off-by: Itxaka <[email protected]>

.github/workflows/reusable-docker-arm-build.yaml

@@ -174,7 +174,7 @@ jobs:
           --set "state_dir=/output" \
           --set "disk.raw=true"
       - name: Upload Image as OCI artifact on release
-        if: ${{ startsWith(github.ref, 'refs/tags/v') }}
+        if: ${{ startsWith(github.ref, 'refs/tags/v') &&  inputs.model != 'rpi3' }}
         run: |
           curl https://luet.io/install.sh | sudo sh
           IMAGE=$(echo "${{ env.IMAGE_REF }}" | sed 's/$/-img/')