issue with build.sh and CI script

Hey, when fixing up my forked bundle to generate mpy files again (CI died after 2yrs of no changes), it had problems with the package names and didn't generate expected assets.

https://github.com/good-enough-technology/CircuitPython_GoodEnough_Bundle/pull/1

This PR was claude working through it with a mini fix until I asked about path based injection as the steps chain, classically it had made things worse...

Anyway, here's a single commit that avoids the chaining risk and fixes the issue.
There's probably a more elegant solution, but my Fable budget is low so this was opus😄

#290

-edit-
` package_folder_prefix is only consulted when a library has no [tool.setuptools] metadata in pyproject.toml. `

Empieza leyendo build.sh y el script de CI; después, compara su comportamiento respecto a los nombres de paquetes y la generación de assets con el pull request del fork y el issue #290 referenciados. Comprueba los metadatos relevantes de pyproject.toml y considera el trabajo completo cuando el bundle genere en CI los assets mpy esperados con los nombres de paquete correctos.

Escrito por el modelo de indexación a partir del texto del issue.