Improve explanation of MR approval settings by clarifying settings location

What does this MR do and why?

Describe in detail what your merge request does and why.

The message in the Setting enforced pop-up could mean that this setting could be changed in the project settings while it could only be changed in the group settings.

This change is to prevent such confusion.

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How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

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• I have evaluated the MR acceptance checklist for this MR.