Remove pgbench "progress" test pending solution of its timing issues.
Remove pgbench "progress" test pending solution of its timing issues.

Buildfarm member skink shows that this is even more flaky than
I thought.  There are probably some actual pgbench bugs here
as well as a timing dependency.  But we can't have stuff this
unstable in the buildfarm, it obscures other issues.

adam8157/gpdb,greenplum-db/gpdb,lisakowen/gpdb,greenplum-db/gpdb,lisakowen/gpdb,50wu/gpdb,50wu/gpdb,adam8157/gpdb,greenplum-db/gpdb,lisakowen/gpdb,xinzweb/gpdb,lisakowen/gpdb,50wu/gpdb,adam8157/gpdb,lisakowen/gpdb,greenplum-db/gpdb,adam8157/gpdb,xinzweb/gpdb,adam8157/gpdb,xinzweb/gpdb,50wu/gpdb,50wu/gpdb,xinzweb/gpdb,lisakowen/gpdb,greenplum-db/gpdb,lisakowen/gpdb,xinzweb/gpdb,lisakowen/gpdb,50wu/gpdb,xinzweb/gpdb,50wu/gpdb,greenplum-db/gpdb,xinzweb/gpdb,adam8157/gpdb,xinzweb/gpdb,adam8157/gpdb,adam8157/gpdb,50wu/gpdb,greenplum-db/gpdb,greenplum-db/gpdb