Add new syntax example for arrow_cast

Author: alamb

docs/source/user-guide/sql/data_types.md

@@ -41,7 +41,18 @@ You can cast a SQL expression to a specific Arrow type using the `arrow_cast` fu
 For example, to cast the output of `now()` to a `Timestamp` with second precision:
 
 ```sql
-select arrow_cast(now(), 'Timestamp(Second, None)');
+select arrow_cast(now(), 'Timestamp(s)') as "now()";
++---------------------+
+| now()               |
++---------------------+
+| 2025-10-24T20:02:45 |
++---------------------+
+```
+
+The older syntax still works as well:
+
+```sql
+select arrow_cast(now(), 'Timestamp(Second, None)') as "now()";
 +---------------------+
 | now()               |
 +---------------------+