Update primary key column limit from 16 to 32

SQL 2017, 2019, 2022, 2025 allow 32 columns as a PK

Author: way0utwest

docs/relational-databases/tables/primary-and-foreign-key-constraints.md

@@ -34,7 +34,7 @@ monikerRange: "=azuresqldb-current || >=sql-server-2016 || >=sql-server-linux-20
 :::image type="content" source="media/primary-and-foreign-key-constraints/composite-primary-key.gif" alt-text="Diagram of rows in a table for a composite PRIMARY KEY constraint.":::
 
 -   A table can contain only one primary key constraint.  
--   A primary key can't exceed 16 columns and a total key length of 900 bytes.  
+-   A primary key can't exceed 32 columns and a total key length of 900 bytes.  
 -   The index generated by a primary key constraint can't cause the number of indexes on the table to exceed 999 nonclustered indexes and 1 clustered index.  
 -   If clustered or nonclustered isn't specified for a primary key constraint, clustered is used if there's no clustered index on the table.  
 -   All columns defined within a primary key constraint must be defined as not null. If nullability isn't specified, all columns participating in a primary key constraint have their nullability set to not null.