Generate images.json for extra_isos phase

JIRA: RHELCMP-7241
Signed-off-by: Haibo Lin <hlin@redhat.com>

pungi/scripts/pungi_koji.py

@@ -553,6 +553,7 @@ def run_compose(
         buildinstall_phase.skip()
         and ostree_installer_phase.skip()
         and createiso_phase.skip()
+        and extra_isos_phase.skip()
         and liveimages_phase.skip()
         and livemedia_phase.skip()
         and image_build_phase.skip()