Buildbot kills the "test" step because it takes longer than 3 hours, whereas Python regrtest gets a timeout of 3 hour 15 min.

Refleak buildbots should get a longer timeout for the "test" step.

PPC64LE Fedora Rawhide Refleaks 3.10:
https://buildbot.python.org/all/#/builders/603/builds/7

./python  ./Tools/scripts/run_tests.py -j 1 -u all -W --slowest --fail-env-changed --timeout=11700 -R 3:3 -u-cpu -j10 
WARNING: Disable --verbose3 because it's incompatible with --huntrleaks: see http://bugs.python.org/issue27103
== CPython 3.10.0b1+ (heads/3.10:9a0e65c8e0, May 10 2021, 00:01:01) [GCC 11.1.1 20210428 (Red Hat 11.1.1-1)]
== Linux-5.7.0-0.rc0.git2.1.fc33.ppc64le-ppc64le-with-glibc2.33.9000 little-endian
== cwd: /home/buildbot/buildarea/3.10.cstratak-fedora-rawhide-ppc64le.refleak/build/build/test_python_1529753æ
== CPU count: 8
== encodings: locale=UTF-8, FS=utf-8
Using random seed 1661030
0:00:00 load avg: 3.25 Run tests in parallel using 10 child processes (timeout: 3 hour 15 min, worker timeout: 3 hour 20 min)
0:00:00 load avg: 3.25 [  1/427] test_tix skipped (resource denied)
(...)
2:58:49 load avg: 0.00 running: test_asyncio (2 hour 58 min)
2:59:19 load avg: 0.00 running: test_asyncio (2 hour 58 min)
2:59:49 load avg: 0.00 running: test_asyncio (2 hour 59 min)

command timed out: 10800 seconds elapsed running [b'make', b'buildbottest', b'TESTOPTS=-R 3:3 -u-cpu -j10 ${BUILDBOT_TESTOPTS}', b'TESTPYTHONOPTS=', b'TESTTIMEOUT=11700'], attempting to kill