Remove reference to bootstrap alert

What does this MR do and why?

Remove reference to bootstrap alert

• alert class is used with bootstrap
• remove missed class reference

Screenshots or screen recordings

Before	After

How to set up and validate locally

• Select a project
• Navigate to Operations/Tracing
• Force an error

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 #233688 (closed)