chore: remove pages collections from demo (#3915)

dev-test/config.yml

@@ -245,14 +245,3 @@ collections: # A list of collections the CMS should be able to edit
               - { label: 'Date', name: 'date', widget: 'date' }
               - { label: 'Image', name: 'image', widget: 'image' }
               - { label: 'File', name: 'file', widget: 'file' }
-  - name: pages # a nested collection
-    label: Pages
-    label_singular: 'Page'
-    folder: _pages
-    create: true
-    nested: { depth: 100 }
-    fields:
-      - label: Title
-        name: title
-        widget: string
-    meta: { path: { widget: string, label: 'Path', index_file: 'index' } }