Fixed spacing below the merge widgets title

What does this MR do and why?

Adds the correct spacing below the title in the merge request widget

Screenshots or screen recordings

How to set up and validate locally

• View a merge request
• Create a unresolved discussion
• Change browser size to mobile
• See spacing below the title

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.

Closes #376028 (closed)