Don't know of anything offhand. Last year I remember something attempted to do the same thing, but abandoned it. Same reason. The info was in a post. Other than a specific Community where anyone who finds contest can contribute to it, I just don't know.
Did you search to see if there is a Contests Community? Otherwise, people just search the #contest tag.
I'll ask around.
I think the best way to grow this list is that the individuals in the community need to contribute to this post, if they find a contest that is not on this list should comment with the details. There is heaps of contests when you search using #contest tag, I just need to include them in the main post.