feat: add support for merge queues in repository rulesets

[MXfive]

Resolves #1481

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Before the change?

• Does not support merge queue rules on rulesets.

After the change?

• Supports merge queue rules on rulesets

Pull request checklist

• [x] Tests for the changes have been added (for bug fixes / features)
• [x] 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
• [x] No

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