pandoc-3.10: test/command/9090.md

```
% pandoc -f html -t gfm
<table>
  <tr>
    <th>invalid head cell</td>
  </tr>
  <tr>
    <td>body cell</td>
  </tr>
</table>
^D
| invalid head cell |
|-------------------|
| body cell         |
```