Textile → gfm: `<pre>` tag messes up unordered list

Here's a weird one. ;-) Tested with the latest Pandoc 3.0 in the online demo and with a build from Master from a few days ago on my server.

### Original Textile:
```
* List item #1
* List item #2 with

something

### Pandoc converted to `gfm`:
```
\* List item \#1

\* List item \#2 with

something

tags
```

### Expected output:
```
- List item #1
- List item #2 with `something` tags
```

Reproduce the conversion with the Textile input and Pandoc 3.0 or a current master build, then compare the generated GFM with the expected list and inline-code output. Inspect the conversion handling for

 tags inside unordered lists; the work is done when the example produces the expected GFM without escaped list markers or split paragraphs.

Written by the indexing model from the issue text.