Parody posts should always be later than the original

See https://old.reddit.com/r/math/comments/1q77k7s/why_is_233_so_special/nzdr4zv/.

This is an /r/math post which was posted in 2026. However, the bot detects an /r/AnarchyMath "parody" which was posted in 2022. Clearly this isn't a parody post, just a post that happens to have a similar title.

The bot should check that the parody post was made *after* the original.