Fix duplicate items in CREATE USER and ALTER USER (#21939)

Author: dveeden

sql-statements/sql-statement-alter-user.md

@@ -20,12 +20,6 @@ UserSpecList ::=
 UserSpec ::=
     Username AuthOption
 
-RequireClauseOpt ::=
-    ( 'REQUIRE' 'NONE' | 'REQUIRE' 'SSL' | 'REQUIRE' 'X509' | 'REQUIRE' RequireList )?
-
-RequireList ::=
-    ( "ISSUER" stringLit | "SUBJECT" stringLit | "CIPHER" stringLit | "SAN" stringLit | "TOKEN_ISSUER" stringLit )*
-
 Username ::=
     StringName ('@' StringName | singleAtIdentifier)? | 'CURRENT_USER' OptionalBraces
 

sql-statements/sql-statement-create-user.md

@@ -20,12 +20,6 @@ IfNotExists ::=
 UserSpecList ::=
     UserSpec ( ',' UserSpec )*
 
-RequireClauseOpt ::=
-    ( 'REQUIRE' 'NONE' | 'REQUIRE' 'SSL' | 'REQUIRE' 'X509' | 'REQUIRE' RequireList )?
-
-RequireList ::=
-    ( "ISSUER" stringLit | "SUBJECT" stringLit | "CIPHER" stringLit | "SAN" stringLit | "TOKEN_ISSUER" stringLit )*
-
 UserSpec ::=
     Username AuthOption