Update rust to 1.88.0-nightly

[auyer]

This base breaks for projects using creates with edition = 2024. Those require rust 1.85+

Example (this is an action run, and the link will expire):

Caused by:
  feature `edition2024` is required

  The package requires the Cargo feature called `edition2024`, but that feature is not stabilized in this version of Cargo (1.81.0-nightly (154fdac39 2024-07-07)).
  Consider trying a more recent nightly release.
  See https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#edition-2024 for more information about the status of this feature.

For my project, I had to re-built a simples version of this image from the base builder. auyer/Protonup-rs#47