Remove remaining future tense issues

What does this Merge Request do?

Contributes to: gitlab#284446 (closed).

Removes remaining future tense issues from the documentation in this project (follows !1688 (merged)) and elevated test to error to avoid regressions.

Merge Request checklist

• Tests added for new functionality. If not, please raise Issue to follow-up.
• This change is backward compatible. If not, please include steps to communicate to our users.
• Documentation added/updated, if needed.
• gdk doctor test added, if needed.