chore: replace Ring with RustCrypto in pki.rs

[rjzak]

Added "BSD-3-Clause" license to deny.toml since it's used by a RustCrypto dependency.

Signed-off-by: Richard Zak [email protected]

[rjzak]

The only failure is Cargo/deny being upset about the RustCrypto project using a crate called subtle which is BSD-licensed, and that's approved?

[npmccallum]

The only failure is Cargo/deny being upset about the RustCrypto project using a crate called subtle which is BSD-licensed, and that's approved?

Yes. Add it to deny.toml. In the future, do that presumptively and point out the additional license in the PR text so that reviewers can assess whether that change is acceptable or not.