Make test_decoding ddl.out shorter
Some of the test_decoding test output was extremely wide, because it
deals with massive toasted values, and the aligned mode causes psql to
produce 200kB of whitespace and dashes. Change to unaligned mode
temporarily to avoid that behavior.
Backpatch to 14, where it applies cleanly.
Discussion: https://postgr.es/m/
20230405103953.sxleixp3uz5lazst@alvherre.pgsql