pgsql: Revert test added by commit d207038053.

Revert test added by commit d207038053.

This test was trying to test the mechanism to release kernel FDs as needed
to get us under the max_safe_fds limit in case of spill files.  To do that,
it needs to set max_files_per_process to a very low value which doesn't
even permit starting of the server in the case when there are a few already
opened files.  This test also won't work on platforms where we use one FD
per semaphore.

Backpatch-through: 10, till where this test was added
Discussion:
https://postgr.es/m/CAA4eK1LHhERi06Q+MmP9qBXBBboi+7WV3910J0aUgz71LcnKAw@mail.gmail.com
https://postgr.es/m/6485.1578583522@sss.pgh.pa.us

Branch
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REL_12_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/fa1eaebfad436f58a8e6d0201f334edd2553b3d2

Modified Files
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src/test/recovery/t/006_logical_decoding.pl | 39 +----------------------------
1 file changed, 1 insertion(+), 38 deletions(-)