pg_publication_tables show dropped columns

Hi everyone,

Just trying the new column/row filter on v15, I found this issue that
could be replicated very easily.

"""
postgres=# create table t1(i serial primary key);
CREATE TABLE
postgres=# alter table t1 drop i;
ALTER TABLE
postgres=# alter table t1 add id serial primary key;
ALTER TABLE
postgres=# create publication pub_t1 for table t1;
CREATE PUBLICATION

postgres=# select * from pg_publication_tables where pubname = 'pub_t1' \gx
-[ RECORD 1 ]---------------------------------
pubname    | pub_t1
schemaname | public
tablename  | t1
attnames   | {........pg.dropped.1........,id}
rowfilter  |
"""

This could be solved by adding a "NOT attisdropped", simple patch
attached.

-- 
Jaime Casanova
Director de Servicios Profesionales
SystemGuards - Consultores de PostgreSQL