Prepare release v274

[heroku-linguist]

Commits since the last release:

• Remove Python 3.8 support + deprecate Python 3.9 (Remove Python 3.8 support + deprecate Python 3.9 #1732)

For the full diff, see the compare view:
v273...main

[edmorley]

Published:

Creating GitHub release...
https://github.com/heroku/heroku-buildpack-python/releases/tag/v274

Publishing to the Heroku Buildpack Registry...
Two-factor code: ********************************************
Publishing buildpack heroku/python... done
Publishing buildpack was successful

 Version Released At              Status    
 ─────── ──────────────────────── ───────── 
 274     2025-01-08T12:26:15.534Z published