Remove redundant 'vacuum_ao_co' TINC test.

There are plenty of VACUUMs on append-only tables elsewhere in the
regular regression suite, e.g. in 'vacuum_gp', 'appendonly', 'aocs',
uao_compaction tests, and many more.

src/test/tinc/tincrepo/mpp/gpdb/tests/storage/access_methods/appendonly_read_check/sql/vacuum_ao_co.sql

---First try AO
-drop table if exists ao1;
-create table ao1(a int, b int) with(appendonly=true);
-insert into ao1 select i, 10 from generate_series(1, 1000) i;
-update ao1 set b = b + 1;
-vacuum ao1;
-select * from ao1;
-
---Next try CO
-drop table if exists co1;
-create table co1(a int, b int) with(appendonly=true, orientation=column);
-insert into co1 select i, 10 from generate_series(1, 1000) i;
-update co1 set b = b + 1;
-vacuum co1;
-select * from co1;

src/test/tinc/tincrepo/mpp/gpdb/tests/storage/access_methods/appendonly_read_check/test_ao_read_check.py

@@ -71,14 +71,6 @@ class AppendOnlyReadCheckTests(MPPTestCase):
                         line = line.replace('<relfilenode_oid>', str(relfilenode_oid))
                     fp1.write(line)
 
-    def test_vacuum_appendonly(self):
-        out_file = os.path.join(self.output_dir, 'vacuum_ao_co.out')
-        ans_file = os.path.join(self.ans_dir, 'vacuum_ao_co.ans')
-        sql_file = os.path.join(self.sql_dir, 'vacuum_ao_co.sql')
-        PSQL.run_sql_file(sql_file, out_file=out_file)
-        if not Gpdiff.are_files_equal(out_file, ans_file):
-            raise Exception('Vacuum table failed for append only tables !')
-
     def test_pg_aoseg_corruption(self):
         self.create_appendonly_tables()
         config = GPDBConfig()