Prepare release v329

[heroku-linguist]

Commits since the last release:

• Bump pipenv from 2025.0.4 to 2026.0.3 (Bump pipenv from 2025.0.4 to 2026.0.3 #2000)

For the full diff, see the compare view:
v328...main

[edmorley]

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

- Updated Pipenv from 2025.0.4 to 2026.0.3. ([#2000](https://github.com/heroku/heroku-buildpack-python/pull/2000))

Deploy as v329 [y/n]? y

Creating GitHub release...
https://github.com/heroku/heroku-buildpack-python/releases/tag/v329

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

 Version Released At              Status    
 ─────── ──────────────────────── ───────── 
 329     2026-01-08T10:08:22.815Z published