Prepare release v278

[heroku-linguist]

Commits since the last release:

• Update changelog links and tests after Git tag archival (Update changelog links and tests after Git tag archival #1752)
• Change the editable VCS directory location for pip and Pipenv (Change the editable VCS directory location for pip and Pipenv #1753)
• Improve package manager tests (Improve package manager tests #1754)
• make run workflow improvements (make run workflow improvements #1755)
• Rewrite editable VCS paths at build time too (Rewrite editable VCS paths at build time too #1756)
• Bump the ruby-dependencies group with 4 updates (Bump the ruby-dependencies group with 4 updates #1757)

For the full diff, see the compare view:
v277...main

[edmorley]

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

- Added build-time rewriting of editable VCS dependency paths (in addition to the existing run-time rewriting), to work around an upstream Pipenv bug with editable VCS dependencies not being reinstalled correctly for cached builds. ([#1756](https://github.com/heroku/heroku-buildpack-python/pull/1756))
- Changed the location of repositories for editable VCS dependencies when using pip and Pipenv, to improve build performance and match the behaviour when using Poetry. ([#1753](https://github.com/heroku/heroku-buildpack-python/pull/1753))

Deploy as v278 [y/n]? y

Creating GitHub release...
https://github.com/heroku/heroku-buildpack-python/releases/tag/v278

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

 Version Released At              Status    
 ─────── ──────────────────────── ───────── 
 278     2025-02-24T09:22:52.440Z published