Prepare release v276

[heroku-linguist]

Commits since the last release:

• Tests: Misc package manager test improvements (Tests: Misc package manager test improvements #1738)
• Update make target in bin/report debug instructions (Update make target in bin/report debug instructions #1739)
• Bump the ruby-dependencies group with 2 updates (Bump the ruby-dependencies group with 2 updates #1742)
• Deprecate support for the runtime.txt file (Deprecate support for the runtime.txt file #1743)
• Add support for Python 3.13.2 and 3.12.9 (Add support for Python 3.13.2 and 3.12.9 #1744)

For the full diff, see the compare view:
v275...main

[edmorley]

https://github.com/heroku/heroku-buildpack-python/releases/tag/v276

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

- The Python 3.13 version alias now resolves to Python 3.13.2. ([#1744](https://github.com/heroku/heroku-buildpack-python/pull/1744))
- The Python 3.12 version alias now resolves to Python 3.12.9. ([#1744](https://github.com/heroku/heroku-buildpack-python/pull/1744))
- Deprecated support for the `runtime.txt` file. ([#1743](https://github.com/heroku/heroku-buildpack-python/pull/1743))
- Improved the error messages shown when `.python-version`, `runtime.txt` or `Pipfile.lock` contain an invalid Python version. ([#1743](https://github.com/heroku/heroku-buildpack-python/pull/1743))

Deploy as v276 [y/n]? y

Creating GitHub release...
https://github.com/heroku/heroku-buildpack-python/releases/tag/v276

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

 Version Released At              Status    
 ─────── ──────────────────────── ───────── 
 276     2025-02-05T12:08:16.016Z published