pgsql: Attempt to fix newly added Memoize regression test

Attempt to fix newly added Memoize regression test

Both drongo and fairywren seem not to like a new regression test added
by 2cca95e17. These machines show a different number of actual rows in
the EXPLAIN ANALYZE output. Since the number of actual rows is divided by
the number of loops, I suspect this might be due to some platform
dependant rounding behavior as the total row count is 5 and the number of
loops is 2. drongo and fairywren seem to be calculating that 5.0 / 2.0 is
3, whereas most other machines think the answer is 2.

Here we tweak the test query's WHERE clause so it's 4.0 / 2.0 instead.
There shouldn't be too much wiggle room for platform dependant-behavior to
be a factor with those numbers.

Reported-by: Tom Lane
Discussion: https://postgr.es/m/1035225.1706301718%40sss.pgh.pa.us

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/a3a836fb5e51183eae624d43225279306c2285b8

Modified Files
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src/test/regress/expected/memoize.out | 12 ++++++------
src/test/regress/sql/memoize.sql | 4 ++--
2 files changed, 8 insertions(+), 8 deletions(-)