zsh: support `;|` case clause terminator

❌ Fails to parse for `;|`

```bash
./shfmt --language-dialect zsh <<<'case x in
  a) echo a ;|
  b) echo b ;;
esac'
# <standard input>:2:14: `|` can only immediately follow a statement
```

✅ `;;` and `;&` work fine.

### zsh docs

https://zsh.sourceforge.io/Doc/Release/Shell-Grammar.html#Complex-Commands
