delete_old_oci_images: manage repositories that don't have tags

Signed-off-by: Clement Verna <cverna@tutanota.com>

library/delete_old_oci_images.py

@@ -112,8 +112,13 @@ def main():
         if not resp.ok:
             result["stdout_lines"].append("Failed to get the list of tags for {}".format(repo))
 
-        # For each tag get the maninfest
+
         image = resp.json()
+        # Log the repositories that don't have any tags
+        if image["tags"] is None:
+          result["stdout_lines"].append("{repo} does not have any tags".format(repo))
+          continue
+        # For each tag get the maninfest
         for tag in image["tags"]:
             resp = s.get("{}/v2/{}/manifests/{}".format(registry, repo, tag))
             if not resp.ok: