docs: Fix typo

Author: igorlukanin

docs/pages/guides/recipes/analytics/xirr.mdx

@@ -56,7 +56,6 @@ cubes:
 
     # Everything below this line is only needed for querying
     # pre-aggregations in Cube Store
-    dimensions:
       - name: date__day
         sql: "{date.day}"
         type: time