tests: bump default timeout to 360s A number of tests hit or almost hit the default limit even on modern hardware. While the tests are ideally split into smaller pieces, that's non-trivial work. HyperThreading and similar technologies can trigger this often, even without any other load on the machine. Differential Revision: https://phab.mercurial-scm.org/D10534

#require docutils gettext

  $ $TESTDIR/check-gendoc da
  checking for parse errors