Fix text alignment in vulnerability timeline

What does this MR do and why?

Fixes the note header and note body text not being aligned in the vulnerability details timeline and vulnerability modal.

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. You'll need an EE License
2. You'll need to have runners enabled (See $2408961 for setting up a runner)

Steps:

Vulnerability details timeline

1. Open the vulnerability report page on a repository with vulnerabilities and click on a specific one
2. Create a timeline by changing the status of the vulnerability
3. Add a comment to such a status update in the timeline
4. Validate that the note header and note body of the comment are aligned

Vulnerability modal

1. Import https://gitlab.com/gitlab-examples/security/security-reports
2. Create a new MR by modifying a file
3. Toggle security reports
4. Find a finding, click on it and dismiss with adding a comment
5. Open the same finding and validate that note header "Administrator" is aligned with note body "Dismissed..." / the comment you added to dismiss

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 #367719 (closed)