upgrade ed25519-dalek to 2.0.0-rc.2

[dmitris]

Summary

Update ed25519-dalek dependency to 2.0.0-rc.2 with the necessary code and Cargo.toml adjustments.

Some formatting changes in Cargo.toml are done automatically by VSCode (breaking longer lines into multiple ones), here are the "real" changes of the dependencies:

- ed25519 = { version = "=2.1", features = ["alloc"] }
- ed25519-dalek = { version = "2.0.0-pre.0", features = ["pkcs8", "rand_core"] }
+ ed25519 = { version = "2.2.1", features = ["alloc"] }
+ ed25519-dalek = { version = "2.0.0-rc.2", features = ["pkcs8", "rand_core"] }
[...]
+ spki = { version = "0.7.2", features = ["pem", "std"] }

Closes #262.

Release Suggestion

Since this would be changing dependencies, it may be worth to cut a "checkpoint" 0.6.1 release before merging this PR.

Release Note

• updated dependencies: ed25519-dalek to 2.0.0-rc.2 and ed25519 - to 2.2.1.

Documentation

No changes.

[flavio]

OMG, thanks for this update. It was on my TODO list since a long time

[flavio]

Since this would be changing dependencies, it may be worth to cut a "checkpoint" 0.6.1 release before merging this PR.

I think we cannot do that, since we've already merged some breaking API changes into the main branch.

I would merge this PR, take a look at the remaining deps that need to be updated and then cut a 0.7 release.

How do the other @sigstore/sigstore-rs-codeowners feel about that?

[flavio]

Cool, merging based on the reaction of the other maintainers