Merge branch 'thiserror2' into 'master'

Update to thiserror 2.0 and add Cargo.lock

See merge request redox-os/users!40

0.4.3 - add allow opening files without write access, using shared lock

0.4.2 - fix build without default features

0.4.1: Make AllUsers::new public

See gitlab release notes

Bump argon version and make argon an optional dependency