Support pypy binary installs without python-build

[jdx]

Discussed in #3866

^{Originally posted by scop December 29, 2024}
Would be nice to support pypy installs without delegating to python-build, i.e. with python.compile set to false in settings.

So e.g. mise install [email protected] would work.

• release tags: https://github.com/pypy/pypy/tags
• binary downloads: https://pypy.org/download.html