Remove expensive call in build badge

We don't need to list all the tags to determine if any exist, and showing the repo is ready when it is empty is probably correct behavior anyway

data/model/repository.py

@@ -616,3 +616,14 @@ def list_popular_public_repos(action_count_threshold, time_span, repo_kind='imag
           .group_by(RepositoryActionCount.repository, Repository.name, Namespace.username)
           .having(fn.Sum(RepositoryActionCount.count) >= action_count_threshold)
           .tuples())
+
+
+def is_empty(namespace_name, repository_name):
+  """ Returns if the repository referenced by the given namespace and name is empty. If the repo
+      doesn't exist, returns True.
+  """
+  try:
+    tag.list_repository_tags(namespace_name, repository_name).limit(1).get()
+    return False
+  except RepositoryTag.DoesNotExist:
+    return True