[FEAT]: add support for custom properties apis

[Jeremy-Walton]

Describe the need

https://docs.github.com/en/rest/orgs/custom-properties?apiVersion=2022-11-28

Looks like this was already added to the .net version but I don't see it available here. octokit/octokit.net#2832

SDK Version

No response

API Version

No response

Relevant log output

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Code of Conduct

• I agree to follow this project's Code of Conduct

[github-actions]

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