According to the migration guide, the <pre> element ("format_pre") is no longer available in CKEditor 5.
However, I was still able to configure it as a formatting option for CKEditor 5 using the options for the heading:
{ model: 'formatted', view: 'pre', title: 'Formatted' }
Is this correct or should <pre> elements (markup created with CKEditor 4) be replaced by code blocks (<pre><code>...</code></pre>)?
I think this works because it is possible to define custom elements for the heading