🧵 Wait for UI state to be processed before saving

There's a possible race condition here that the clicks happen too
quickly and the state change was not processed yet and the old state
is then sent to the backend.

src/openforms/forms/tests/e2e_tests/test_form_designer.py

@@ -1505,6 +1505,9 @@ def setUpTestData():
             await page.goto(str(admin_url))
 
             await page.get_by_label("Appointment enabled").click()
+            await expect(
+                page.get_by_role("tab", name="Steps and fields")
+            ).not_to_be_visible()
 
             with phase("save form changes to backend"):
                 await page.get_by_role("button", name="Save", exact=True).click()