gh-94673: Fix _PyTypes_InitTypes() and get_type_attr_as_size()

[ericsnowcurrently]

This change has two small parts:

1. a follow-up to gh-94673: Ensure Builtin Static Types are Readied Properly #103940 with one case I missed
2. adding a missing return that I noticed while working on related code

• Issue: [subinterpreters] Static types incorrectly share some objects between interpreters #94673