feat: Add github_organization_repositories data source

[borchero]

Resolves #2484

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Before the change?

see issue

After the change?

• There exists a new github_organization_repositories data source providing details about all repositories in an organization
  • The set of details returned is kept small for now (both to gauge an understanding of whether this can make it into the provider and to not unnecessarily blow up the API from the get-go)

Pull request checklist

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)

Does this introduce a breaking change?

Please see our docs on breaking changes to help!

• Yes
• No

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