Prepare release v307

[heroku-linguist]

Commits since the last release:

• Deprecate implicit setup.py support (Deprecate implicit setup.py support #1897)

For the full diff, see the compare view:
v306...main

[edmorley]

$ make publish
Checking environment...
Checking buildpack versions in sync...
Extracting changelog entry for this release...

- Deprecated support for falling back to installing dependencies from a `setup.py` file if no Python package manager files were found. ([#1897](https://github.com/heroku/heroku-buildpack-python/pull/1897))

Deploy as v307 [y/n]? y

Creating GitHub release...
https://github.com/heroku/heroku-buildpack-python/releases/tag/v307

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

 Version Released At              Status    
 ─────── ──────────────────────── ───────── 
 307     2025-09-10T14:03:48.313Z published