Update ed25519-dalek to allow rust-analyzer to work properly

[ShadowJonathan]

From #3, this is currently blocked as-is.

I'm converting that PR into an issue to track this problem, as ed25519-dalek has gone two years without a release, with some improvements on master branch that should be in a normal release.

Original issue, which is now closed as fixed, but not in a release yet: https://github.com/dalek-cryptography/ed25519-dalek/issues/173

Issue on their repo calling for a new release: https://github.com/dalek-cryptography/ed25519-dalek/issues/192

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Alternatively, the following could be added to .vscode/settings.json to fix this for everyone using vscode;

  "rust-analyzer.cargo.unsetTest": [
    "core",
    "ed25519-dalek"
  ],