As a Watchlist Expiry user, I want the label in for "Watchlist time period" removed from the legacy source editor, so that the watch features are not awkwardly split into two separate rows.
Background: This is a follow-up to T248494#6375651. The watchlist expiry dropdown in the edit form currently has a label above it, which makes the whole row of checkboxes etc. take up more vertical space than it needs to. One fix is for the label to be inline with the widget, but this is blocked on T251590: Inline FieldLayout isn't inline when it contains a TextInputWidget. Another (easier) fix is to remove just this one field's label from display (but keep it for screen readers etc.).
- Remove the label for "Watchlist time period" in the legacy source editor
- There should be only one line/row (rather than 2) for watchlist related features after these changes are made