Prepare release v259

[heroku-linguist]

Commits since the last release:

• Bump rubocop-rspec from 3.0.5 to 3.1.0 in the ruby-dependencies group (Bump rubocop-rspec from 3.0.5 to 3.1.0 in the ruby-dependencies group #1653)
• Enable remaining optional Shellcheck rules (Enable remaining optional Shellcheck rules #1654)
• Enable Bash's inherit_errexit (Enable Bash's inherit_errexit #1655)
• Add support for Python 3.9 on Heroku-24 (Add support for Python 3.9 on Heroku-24 #1656)
• Add additional buildpack metrics (Add additional buildpack metrics #1657)
• Refactor Python version handling (Refactor Python version handling #1658)

For the full diff, see the compare view:
v258...main

[edmorley]

$ make publish
Deploy as version: v259 [y/n]? y

Tagging commit 5a6ec71813bc26fb8bb4614f3ac26db11c5785e0 with v259... 
Total 0 (delta 0), reused 0 (delta 0), pack-reused 0 (from 0)
To https://github.com/heroku/heroku-buildpack-python
 * [new tag]         v259 -> v259

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

 Version Released At              Status    
 ─────── ──────────────────────── ───────── 
 259     2024-10-09T08:50:48.208Z published