Remove unnecessary gl-alert-dismiss class

What does this MR do and why?

Describe in detail what your merge request does and why.

Remove unnecessary gl-alert-dismiss class

• the class has no css or funcationality associated with it
• It was added as part of the migration in !88449 (merged), but it isn't necessary

Changelog: other

Screenshots or screen recordings

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No Visual change

before	after

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. Navigate to a project => Repository => Tags => New Tag (http://gdk.test:3443/h5bp/html5-boilerplate/-/tags/new)
2. Enter !@#$%^&* as the Tag name and click Create tag

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 #325382 (closed)