Remove spinner when approval require input is changed

Issue: #38090 (closed)

What does this MR do?

When "No.approvals required" is changed, there is a spinner that appears below it. This MR removes that for a better experience with no odd spinner hops.

Testing Case

1. Navigate to General project settings
2. Expand the Merge request approvals section
3. Increase/decrease the no. of required approvals for any approval rule.
4. No spinner should appear

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• 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

Closes #38090 (closed)