pgsql: oauth_validator: Remove racing GUC check

oauth_validator: Remove racing GUC check

Follow-up to bca67e5a3. The test added there changed the value of
oauth_validator_libraries, waited for the postmaster to apply it, and
verified the change on an existing background connection. But there's no
guarantee that the SIGHUP will have arrived and completed its work on
existing backends by that time, so the final test flaked.

We only care about the postmaster's state here, since we're testing the
GUC's effects on newly forked backends, so remove the background check
entirely.

Per buildfarm member serinus.

Reported-by: Alexander Lakhin <exclusion(at)gmail(dot)com>
Discussion: https://postgr.es/m/a37a3cea-5bd8-4385-a1d4-bb89394c079c%40gmail.com
Backpatch-through: 18

Branch
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REL_18_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/af28fc13e20db49d559c00a8156753090c5516fd

Modified Files
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src/test/modules/oauth_validator/t/001_server.pl | 2 --
1 file changed, 2 deletions(-)