Snapcraft: Update example Rust snap to core24

[medubelko]

Background

In Craft a Rust app, the XSV snap is built on core18, which is severely out-of-date.

This is a great opportunity to learn how to build a simple snap.

Request

Copy the snapped XSV project to the Craft Examples repo.

Change the base to core24, ensure it builds and tests correctly.

Guidelines

Review the Snapcraft contribution guidelines.

The existing document and the Snapcraft tutorial should contain enough information to get you started building the snap.