v5.2 Alert color is disabled
Created by: cccabinet
The alert setting was changed to a CSS variable in #35401, but the alert color is disabled.
v5.1.3(https://getbootstrap.com/docs/5.1/components/alerts/#examples)
v5.2.0(https://deploy-preview-35401--twbs-bootstrap.netlify.app/docs/5.1/components/alerts/#examples)
Please correct it.