CPython 3.8 reached EOL on 2024-10-07.
CPython 3.13t (a.k.a. free-threading, no-gil) was experimental, it has little use now that CPython 3.14t is available (and no longer experimental). It's also worth noting that free-threading fixes are not always backported in CPython 3.13 given its experimental status.

Dropping CPython 3.8 & 3.13t will allow adding CPython 3.15 with minimal size / build time impact on images (3.15b0 is expected on 2025-05-05).