[3.14] gh-145685: Improve scaling of type attribute lookups (gh-145774) (#145874)

Avoid locking in the PyType_Lookup cache-miss path if the type's
tp_version_tag is already valid.

(cherry picked from commit cd5217283112d41c0244e2d96302cbe33f0b4cb1)

Co-authored-by: Sam Gross <colesbury@gmail.com>