update cross

[mcandre]

Pending the next cross release.

This is particularly important for:

• Reenabling more Android targets
• Updating more Docker images
• Updating Rust version
• Resolving old cross quirks
• Keeping up with any breaking changes in (pre-1.0) cross

[mcandre]

Lack of Rust 1.68(.2) in the various cross images probably makes the builds slower than they need to be.