Remove incorrect field from information schema

The source code comment already said that the presence of the field
element_types.domain_default might be a bug in the standard, since it
never made sense there.  Indeed, the field is gone in newer versions
of the standard.  So just remove it.

doc/src/sgml/information_schema.sgml

@@ -3134,15 +3134,6 @@ ORDER BY c.ordinal_position;
       </para></entry>
      </row>
 
-     <row>
-      <entry role="catalog_table_entry"><para role="column_definition">
-       <structfield>domain_default</structfield> <type>character_data</type>
-      </para>
-      <para>
-       Not yet implemented
-      </para></entry>
-     </row>
-
      <row>
       <entry role="catalog_table_entry"><para role="column_definition">
        <structfield>udt_catalog</structfield> <type>sql_identifier</type>

src/backend/catalog/information_schema.sql

@@ -2741,8 +2741,6 @@ CREATE VIEW element_types AS
            CAST(null AS character_data) AS interval_type,
            CAST(null AS cardinal_number) AS interval_precision,
 
-           CAST(null AS character_data) AS domain_default, -- XXX maybe a bug in the standard
-
            CAST(current_database() AS sql_identifier) AS udt_catalog,
            CAST(nbt.nspname AS sql_identifier) AS udt_schema,
            CAST(bt.typname AS sql_identifier) AS udt_name,

src/include/catalog/catversion.h

@@ -57,6 +57,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	202307261
+#define CATALOG_VERSION_NO	202308161
 
 #endif