pgsql: Introduce PG_TEST_TIMEOUT_DEFAULT for TAP suite non-elapsing tim

Introduce PG_TEST_TIMEOUT_DEFAULT for TAP suite non-elapsing timeouts.

Slow hosts may avoid load-induced, spurious failures by setting
environment variable PG_TEST_TIMEOUT_DEFAULT to some number of seconds
greater than 180. Developers may see faster failures by setting that
environment variable to some lesser number of seconds. In tests, write
$PostgreSQL::Test::Utils::timeout_default wherever the convention has
been to write 180. This change raises the default for some briefer
timeouts. Back-patch to v10 (all supported versions).

Discussion: https://postgr.es/m/20220218052842.GA3627003@rfd.leadboat.com

Branch
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REL_12_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/8700a487359f121562aa03d36f5f5a61bfc34f8f

Modified Files
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contrib/amcheck/t/002_cic.pl | 3 ++-
contrib/amcheck/t/003_cic_2pc.pl | 14 ++++++++------
src/bin/pg_ctl/t/004_logrotate.pl | 2 +-
src/bin/pg_dump/t/002_pg_dump.pl | 3 ++-
src/bin/scripts/t/080_pg_isready.pl | 4 ++--
src/test/perl/PostgresNode.pm | 17 ++++++++++-------
src/test/perl/TestLib.pm | 6 +++++-
src/test/recovery/t/006_logical_decoding.pl | 4 ++--
src/test/recovery/t/010_logical_decoding_timelines.pl | 4 ++--
src/test/recovery/t/013_crash_restart.pl | 2 +-
src/test/recovery/t/017_shm.pl | 13 +++++++------
11 files changed, 42 insertions(+), 30 deletions(-)