Need to clarify reproducibility of packages built with alpine/wolfi

[Kamillaova]

Currently some packages are built in a alpine/wolfi environment.
There are no repository snapshots in the Alpine and Wolfi repositories, thus reproducibility of the extensions is not guaranteed, as reproducibility may be broken after updating a package in the repositories.

[frezbo]

This is only used for nvidia packages needing glibc requirement and the Xen guest agent needing a rust compiler, everything else should be reproducible as is.

Xen is a community contributed extension and we'll not guarantee any reproducibility

NVIDIA is a core extension and we'll do more work in providing reprodcubility guarantees.

See https://www.talos.dev/v1.11/talos-guides/configuration/system-extensions/#official-system-extension-tiers