workflow: libvirt e2e: cluster clean-up

Clean up the cluster after testing, if running on self-hosted
runners, so that if they aren't thrown away each time, they
don't cause issues on subsequent runs.

Signed-off-by: stevenhorsman <steven@uk.ibm.com>

.github/workflows/e2e_libvirt.yaml

@@ -176,3 +176,7 @@ jobs:
           echo "::endgroup::"
         # Avoid running with `set -e` as command fails should be allowed
         shell: bash {0}
+
+      - name: Clean-up cluster
+        if: ${{ runner.environment == 'self-hosted' }}
+        run: ./libvirt/kcli_cluster.sh delete