Fix: release-iso.yml to not fail if no images are returned (#202)

Builds started failing once #195 was merged. This fixed the release-iso workflow for me.

.github/workflows/release-iso.yml

@@ -35,7 +35,7 @@ jobs:
           GITHUB_TOKEN: ${{ github.token }}
         run: |
           if gh release list -R ${{ github.repository_owner }}/${{ github.event.repository.name }} | grep "auto-iso"; then
-            gh release view auto-iso -R ${{ github.repository_owner }}/${{ github.event.repository.name }} --json assets -q .assets[].name | xargs -L 1 gh release delete-asset auto-iso -R ${{ github.repository_owner }}/${{ github.event.repository.name }}
+            gh release view auto-iso -R ${{ github.repository_owner }}/${{ github.event.repository.name }} --json assets -q .assets[].name | xargs --no-run-if-empty -L 1 gh release delete-asset auto-iso -R ${{ github.repository_owner }}/${{ github.event.repository.name }}
             gh release upload auto-iso ${{ steps.isogenerator.outputs.iso-path }} -R ${{ github.repository_owner }}/${{ github.event.repository.name }} --clobber
           else
             gh release create auto-iso ${{ steps.isogenerator.outputs.iso-path }} -t ISO -n "This is an automatically generated ISO release." -R ${{ github.repository_owner }}/${{ github.event.repository.name }}