Support parsing special cases for `2022.12`/`draft` that we already test for in `2021.12`!

[honno]

After #213, it's not even that we can't parse newly introduced special cases, but that some changes to formatting mean special cases we test for 2021.12 aren't getting tested for >2022.12 now.

[kgryte]

What changes to formatting affected special case parsing?

[honno]

What changes to formatting affected special case parsing?

Good questions... turns out, none! I just introduced a bug when collecting special cases (used break over continue 🤦), resolved by #216.