use more meaningful alias job instead of j in G-3120

Author: PhilippSalvisberg

docs/4-language-usage/3-dml-and-sql/1-general/g-3120.md

@@ -67,8 +67,8 @@ select emp.last_name
       ,emp.first_name
   from employees emp
  where emp.employee_id in (
-          select j.employee_id
-            from jobs j
-           where j.job_title like '%Manager%' -- NOSONAR: G-1050 literal is ok for a standalone query
+          select job.employee_id
+            from jobs job
+           where job.job_title like '%Manager%' -- NOSONAR: G-1050 literal is ok for a standalone query
        );
 ```