Rust 2024 Edition

[vincentberthier]

Trying to use cargo-pgo on a project upgraded to the 2024 edition of Rust fails:
Cannot get cargo metadata: Json(Error("unknown variant 2024, expected one of 2015, 2018, 2021", line: 1, column: 378321))

This is due to version 0.15 of cargo_metadata not allowing 2024 as a valid version. This has been changed in newer versions however, so it might just be a matter of upgrading the dependency (to minimum 0.17.0).

[Kobzol]

Good point! I will do that in #65, although I had some trouble with CI, so I will need to fix that first.

[vincentberthier]

Cool, thanks.