Citations don't work in `authornote`

`abstract: [@citation]` works, but `authornote: [@citation]` doesn't.

Truncated output:
```
  authornote: |
    A paper [@citation]...
  bibliography:
    - bibliography.bib
[typst]: Compiling index.typ to index.pdf...error: cannot format citation in isolation
  = hint: check whether this citation is measured without being inserted into the document
```