Remove redundant lazy_static and once_cell

[senekor]

As of Rust 1.80, the functionality of these two crates has been stabilized in the standard library.

See https://blog.rust-lang.org/2024/07/25/Rust-1.80.0.html#lazycell-and-lazylock

[senekor]

This is will break many solutions. For example, lazy_static was very useful for robot-name. There are two reasons I think it's worth it:

• We cannot guarantee backwards compatibility for the libraries included in the test runner anyway. Bumping the major version of a crate could already break solutions. Including multiple major versions of the same library is infeasible since many libraries are not 1.0 and have semver-breaking changes often.
• The community solutions are supposed to show "how it's done". Using lazy_static is not "how it's done" anymore. Hiding these solutions could be a net positive.