Add native support for ssh keys for age

[musjj]

Adds support for the age's native SSH feature from getsops/sops#1692.

Also deprecates sops.age.sshKeyPaths as it should no longer be necessary.

Closes #744

[folliehiyuki]

sops.age.sshKeyPaths has an advantage of allowing users to specify multiple private SSH key files. This behavior cannot be replicated to sops' native SSH feature.

[srhb]

Anything I can do to help this along?

[Parsifa1]

any update?

[Parsifa1]

as getsops/sops#1692, sops has it's simple key-find procedure: first ~/.ssh/id_ed25519 next ~/.ssh/id_rsa,
maybe for simple usecase, provide a simple option to open it, and a further option to set the custom SEC path.

like :

sops = {
    sshKeyNative = {
        enable = true; #default false
        path = "/foo/bar/id_sra"; # previous `sshKeyPaths`
    };
}

if no sshKeyNative.path set, just using sops's native key-finding procedure , which makes easier for simple use.

that's just my two cents, thanks for you PR :)

[nikhilmaddirala]

Hi, is there anything any of us can do to help move this along? Thank you!