Downcast converters for bookmark

[NavinShrinivas]

📝 Provide detailed reproduction steps (if any)

1. Create a downcast converter plugin for bookmar
2. add a bookmark
3. view the HTML from ckeditor inspector

✔️ Expected result

To stick to what the downcast converter is supposed to do

❌ Actual result

Nothing happens, bookmark continues to be what it was being

❓ Possible solution

If you have ideas, you can list them here. Otherwise, you can delete this section.

📃 Other details

• Browser: Chrome
• OS: MacOS 15.1
• First affected CKEditor version: angular npm version
• Installed CKEditor plugins: bookmark, classic-build

this is the following code for the converter :

 this.editor.conversion.for('downcast').elementToStructure({
      model: 'bookmark',
      view: (modelElement, { writer }) => {
          const element = writer.createContainerElement('span', {
              class: 'bookmark', 
          }, [
            writer.createSlot()
          ]);
          return element;
      }
  });

This converter takes effect, for say heading1 but does not for bookmarks. So I'm certain this issue is with bookmarks only.