Update MSRV to 1.58.0

I would want to have at least Rust 1.58, since the code uses heavily the [format arguments capture](https://blog.rust-lang.org/2022/01/13/Rust-1.58.0.html#captured-identifiers-in-format-strings) feature.

_Originally posted by @x-hgg-x in https://github.com/artichoke/strftime-ruby/pull/12#discussion_r945536314_