Adds methods for actions secrets

[jylitalo]

Still missing all specs for testing these methods, so current status is "works for me".

[indigok]

👋@jylitalo

Thanks for opening this up, we're excited to see this being added. Below are some review changes we'd appreciate seeing that would make it more consistent with the rest of the library. To get this merged, we'll also want to see the specs written! Let us know if you have any questions.

[indigok]

A couple of really helpful things on all the methods would be adding the developer docs link and an options hash, so it would look something like this:

Suggested change

	def get_public_key(repo)
	get "#{Repository.path repo}/actions/secrets/public-key"
	# @see https://developer.github.com/v3/actions/secrets/#get-your-public-key
	def get_public_key(repo, options)
	get "#{Repository.path repo}/actions/secrets/public-key", options

[jylitalo]

Created cdd9c74 based on this comment.

[jylitalo]

On my local machines, this currently fails with:

Failures:

  1) Octokit::Client::ActionsSecrets with repository with a secret .create_or_update_secret updating existing secret returns 204
     Got 0 failures and 2 other errors:

     1.1) Failure/Error: raise error

          Octokit::Unauthorized:
            POST https://api.github.com/user/repos: 401 - Bad credentials // See: https://developer.github.com/v3

[jylitalo]

According to https://github.com/RubyCrypto/rbnacl/wiki/Installing-libsodium#windows we would need some windows specific stuff into workflow.yaml, so that we get libsolidium.dll into test environment.

[pschaumburg]

This solves #1216 right?

[jylitalo]

This solves #1216 right?

I would say that it is only part of the solution, then there are at least artifacts and workflow API calls, which need there own implementations. @see https://developer.github.com/v3/actions/
But the secrets part covers pretty much all that I need to manage via API.

[indigok]

@jylitalo apologies for the late reply. You're welcome to add to workflow.yaml in this PR! And thank you for all the work you've done already 🙇🏻‍♀️

[indigok]

👋🏻 @jylitalo

I'm getting access denied when I try to push to this branch, but if you can update it with 4-stable we should be good to merge. We've since removed the dependency on Windows builds ✨

[jylitalo]

Rebased from 4-stable.

[jylitalo]

https://github.com/Yleisradio/octokit.rb/actions/runs/119094250 already reports that it passes tests, but for some reason it doesn't yet appear here.