Mod tools: move expired featuring to the "inactive" section in the list

[cellio]

meta:289058

Posts can be featured either indefinitely or for a specific date range. If you cancel the featuring of a post, it's listed in the table as "inactive" (we keep the history). If it had an end date that has been reached, though, it stays listed as "active" in the table, though it correctly stops being featured. Over time, these active-not-really posts make it harder to manage the actually-active posts. This isn't a huge problem and I'm marking the priority as low, but it's something we should fix.