Updated the approvers rule removal modal

What does this MR do?

While working in the approval rules area, I noticed the removal modal was rendering the button incorrectly.

This MR updates the removal button to use the new danger variant and make use of the new action-primary and action-cancel props. As well as removing the need for v-html by using GlSprintf instead.

Screenshots (strongly suggested)

Before	After

Does this MR meet the acceptance criteria?

Conformity

• 📋 Does this MR need a changelog?
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  • I have not included a changelog entry because _____.
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• Separation of EE specific content

Availability and Testing

1. Go to a projects settings
2. Open the merge request approval rules area and if you don't have any set, create one
3. Click the delete icon and check that the modal text is correct (singular for 1 approver, plural for multiple) and the remove button is using the danger variant (red)

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

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• [-] Label as security and @ mention @gitlab-com/gl-security/appsec
• [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• [-] Security reports checked/validated by a reviewer from the AppSec team