fix: skip empty name in codegen

An empty name occurs with a client-only schema from juju 3.1.0. No
facades seem to be missing, so skipping the bad entry seems to be the
cleanest solution.

Author: james-garner-canonical

juju/client/facade.py

@@ -350,6 +350,8 @@ def buildTypes(schema, capture):
     for kind in sorted((k for k in schema.types if not isinstance(k, str)),
                        key=lambda x: str(x)):
         name = schema.types[kind]
+        if not name:
+            continue
         if name in capture and name not in NAUGHTY_CLASSES:
             continue
         args = Args(schema, kind)