0.138.2

Refactors

• ♻️ Make app.frontend() return 404 for methods other than GET or HEAD with no static file matches. PR #15863 by @tiangolo.

Internal

• 🔧 Update sponsors: remove Stainless. PR #15862 by @tiangolo.
• ♻️ Refactor how sponsors data is handled for banners. PR #15852 by @tiangolo.