How to remove the "Create New Document" action from a specific part of the document list structure.

// structure/index.ts
import type {StructureResolver} from 'sanity/structure'

export const structure: StructureResolver = (S) =>
  S.list()
    .id('root')
    .title('Content')
    .items([
      // Your nested structure
      S.listItem()
        .title('Programs')
        .child(
          S.list()
            .title('By Department')
            .items([
              S.listItem()
                .title('Departments')
                .child(
                  S.documentList()
                    .title('Departments')
                    .schemaType('department')
                    .filter('_type == "department"')
                    // Remove the + button from this list
                    .initialValueTemplates([])
                ),
              S.listItem()
                .title('Programs')
                .child(
                  S.documentList()
                    .title('Programs')
                    .schemaType('program')
                    .filter('_type == "program"')
                    // Remove the + button from this list too
                    .initialValueTemplates([])
                ),
            ])
        ),
      
      // Keep creation enabled in these main lists
      S.documentTypeListItem('department').title('All Departments'),
      S.documentTypeListItem('program').title('All Programs'),
    ])