Update Commits API reference in protected branches docs

[fstavela]

Why:

Closes #21608

What's being changed (if available, include any code snippets, screenshots, or gifs):

Changed Before you can enable required status checks, you must configure the repository to use the status API. For more information, see "[Repositories](/rest/reference/commits#commit-statuses)" in the REST documentation.

To Before you can enable required status checks, you must configure the repository to use the status API. For more information, see "[Commits](/rest/commits/statuses)" in the REST documentation.

Source	Preview	Production	What Changed
repositories/configuring-branches-and-merges-in-your-repository/defining-the-mergeability-of-pull-requests/about-protected-branches.md	fpt ghec ghes@ 3.6 3.5 3.4 3.3 3.2 ghae	fpt ghec ghes@ 3.6 3.5 3.4 3.3 3.2 ghae

Check off the following:

• I have reviewed my changes in staging (look for the "Automatically generated comment" and click the links in the "Preview" column to view your latest changes).
• For content changes, I have completed the self-review checklist.

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[github-actions]

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The table contains an overview of files in the content directory that have been changed in this pull request. It's provided to make it easy to review your changes on the staging site. Please note that changes to the data directory will not show up in this table.

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Content directory changes

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Source	Preview	Production	What Changed
repositories/configuring-branches-and-merges-in-your-repository/defining-the-mergeability-of-pull-requests/about-protected-branches.md	fpt ghec ghes@ 3.7 3.6 3.5 3.4 3.3 ghae	fpt ghec ghes@ 3.7 3.6 3.5 3.4 3.3 ghae

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fpt: Free, Pro, Team
ghec: GitHub Enterprise Cloud
ghes: GitHub Enterprise Server
ghae: GitHub AE

[cmwilson21]

@fstavela Thank you for opening a PR and linking it to your issue! ✨

I'll get this triaged for review! ⚡

[jhosman]

Thanks for catching this and opening a PR @fstavela! I made an edit to align this closer with our usual style. I'll go ahead and apply those changes for you, and we'll get this merged! 🎉

[github-actions]

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