Remove spacing span for related issue item

What does this MR do?

A related issue item can have an optional remove button on the right:

Currently, if the button is not shown, a hidden <span> the same height as the button is used to make the issue item the same height whether it has the button or not. Without it, the item height will shrink:

Height without button	Height with button

This MR removes the hidden <span> in favor of a class on the text element instead:

Text element before	Text element after

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content

Availability and Testing

• [-] Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done