Add spec to check sticky classes `sticky-top border-bottom-0` are set correctly

We should add spec to check sticky classes sticky-top border-bottom-0 are set correctly.

Additionally, these classes could be swapped for gl- utilities, and we could check if they can be removed from our CSS.

The following discussion from !54299 (merged) should be addressed:

@mrincon started a discussion:

Suggestion (follow up): We should have a spec to check for these classes.