Make a dashboard its widgets: drop the pages and sections nobody drew

backend/tests/api/routes/test_panels.py

@@ -243,7 +243,7 @@ def _dashboard_with(
 ) -> None:
     """A published dashboard carrying these widgets."""
     saved = _dashboard(client, headers, name)
-    saved["pages"] = [{"id": "main", "sections": [{"id": "main", "widgets": widgets}]}]
+    saved["widgets"] = widgets
     written = client.put(f"{DASHBOARDS}/{name}", headers=headers, json=saved)
     assert written.status_code == 200, written.text
     published = client.post(
@@ -706,22 +706,11 @@ def test_a_panels_socket_carries_only_what_it_draws(
     )
 
     saved = _dashboard(client, superuser_token_headers, "panel_socket")
-    saved["pages"] = [
+    saved["widgets"] = [
         {
-            "id": "main",
-            "title": "Overview",
-            "sections": [
-                {
-                    "id": "main",
-                    "widgets": [
-                        {
-                            "id": "w1",
-                            "type": "stat",
-                            "config": {"message": "house.kitchen.temperature"},
-                        }
-                    ],
-                }
-            ],
+            "id": "w1",
+            "type": "stat",
+            "config": {"message": "house.kitchen.temperature"},
         }
     ]
     written = client.put(