Looks like this transition started today with the upload of python3-defaults (3.14.8-1) to unstable.
-- PGP Key ID: 4096R/6750F10AE88D4AF1 Fingerprint: 8182 DE41 7056 408D 6146 50D1 6750 F10A E88D 4AF1
- Bug#1147081: Adding Python 3.15 for forky Sebastiaan Couwenberg
- Bug#1147081: [DKIM] Bug#1147081: Adding Python ... Sebastiaan Couwenberg
