pgsql: Stabilize test_decoding touching with sequences

Stabilize test_decoding touching with sequences

Some of the test_decoding regression tests are unstable due to modifying
a sequence. The first increment of a sequence after a checkpoint is
always logged (and thus decoded), which makes the output unpredictable.
The runs are usually much shorter than a checkpoint internal, so these
failures are rare, but we've seen a couple of them on animals that are
either slow or are running with valgrind/clobber cache/...

Fixed by skipping sequence decoding in most tests, with the exception of
the test aimed at testing decoding of sequences.

Reported-by: Amita Kapila
Discussion: https://postgr.es/m/d045f3c2-6cfb-06d3-5540-e63c320df8bc@enterprisedb.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/a180c2b34de0989269fdb819bff241a249bf5380

Modified Files
--------------
contrib/test_decoding/expected/ddl.out             | 26 +++++++++++-----------
.../test_decoding/expected/decoding_in_xact.out    |  2 +-
contrib/test_decoding/expected/replorigin.out      |  8 +++----
contrib/test_decoding/expected/rewrite.out         |  2 +-
contrib/test_decoding/expected/slot.out            |  6 ++---
contrib/test_decoding/sql/ddl.sql                  | 26 +++++++++++-----------
contrib/test_decoding/sql/decoding_in_xact.sql     |  2 +-
contrib/test_decoding/sql/replorigin.sql           |  8 +++----
contrib/test_decoding/sql/rewrite.sql              |  2 +-
contrib/test_decoding/sql/slot.sql                 |  6 ++---
10 files changed, 44 insertions(+), 44 deletions(-)