pgsql: Reduce running time of jsonb_sqljson test

Reduce running time of jsonb_sqljson test

The test created a 1m row table in order to test parallel operation of
JSON_VALUE. However, this was more than were needed for the test, so
save time by halving it, and also by making the table unlogged.
Experimentation shows that this size is only a little above the number
required to generate the expected output.

Per gripe from Andres Freund

Discussion: https://postgr.es/m/20220406022118.3ocqvhxr6kciw5am@alap3.anarazel.de

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/2ef6f11b0c77ec323c688ddfd98ffabddb72c11d

Modified Files
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src/test/regress/expected/jsonb_sqljson.out | 8 ++++----
src/test/regress/sql/jsonb_sqljson.sql | 4 ++--
2 files changed, 6 insertions(+), 6 deletions(-)