pgsql: Remove no-longer-needed variant expected regression result files

Remove no-longer-needed variant expected regression result files.

numerology_1.out and float8-small-is-zero_1.out differ from their
base files only in showing plain zero rather than minus zero for
some results. I believe that in the wake of commit 6eb3eb577,
we will print minus zero as such on all IEEE-float platforms
(and non-IEEE floats are going to cause many more regression diffs
than this, anyway). Hence we should be able to remove these and
eliminate a bit of maintenance pain. Let's see if the buildfarm
agrees.

Discussion: https://postgr.es/m/29037.1539021687@sss.pgh.pa.us

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/6eb4378d53b58658c91e4a31d2511a15e6fbf088

Modified Files
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.../regress/expected/float8-small-is-zero_1.out | 584 ---------------------
src/test/regress/expected/numerology_1.out | 136 -----
2 files changed, 720 deletions(-)