Move force push section to match the mockups

What does this MR do and why?

Updates styling of the force push section on the Branch rules details page to match design mockups.

Screenshots or screen recordings

before	after

How to set up and validate locally

1. Enable the branch_rules feature flag.
2. Add a protected branch.
3. Navigate to Settings > Repository > Branch rules > Details.
4. The Force push section should be displayed correctly.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

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

Related to #389058 (closed)