pgsql: Back off output precision in circle.sql regression test.

Back off output precision in circle.sql regression test.

We were setting extra_float_digits = 0 to avoid platform-dependent
output in this test, but that's still able to expose platform-specific
roundoff behavior in some new test cases added by commit a3d284485,
as reported by Peter Eisentraut. Reduce it to -1 to hide that.

(Over in geometry.sql, we're using -3, which is an ancient decision
dating to 337f73b1b. I wonder whether that's overkill now. But
there's probably little value in trying to change it.)

Back-patch to v12 where a3d284485 came in; there's no evidence that
we have any platform-dependent issues here before that.

Discussion: /messages/by-id/15551268-e224-aa46-084a-124b64095ee3@2ndquadrant.com

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/faee5a12ecf13190d7ca11d6dcc7078e494f46ca

Modified Files
--------------
src/test/regress/expected/circle.out | 15 ++++++++-------
src/test/regress/sql/circle.sql | 5 +++--
2 files changed, 11 insertions(+), 9 deletions(-)