test: pin the number of CPU for
issue4074 tests
On machine with an hundreds of CPUs, the "user" CPU time reported can be
inflated by the status steps. Since the test especially focus on the diff
computation, we restrict the number of CPU to avoid potential issues.
Differential Revision: https://phab.mercurial-scm.org/D8112
#
# Avoid interference from actual test env:
unset HGTEST_JOBS
unset HGTEST_TIMEOUT
unset HGTEST_PORT
unset HGTEST_SHELL