Previously this test was passing not because the VA was returning early,
but because the fake HTTP server was only sleeping for 1000 nanoseconds
instead of 1000 milliseconds. The test cases were not exercising the
VA's early-return codepath, because they do not include sufficiently
high ratios of passing or failing remotes to hit quorum early.
Fix the sleep time so the fake HTTP server works as expected, and reduce
the (desired) sleep time from 1000ms to 100ms because that's more than
sufficient for the behavior we're testing.
Fix and diversify the test cases to actually hit positive or negative
quorum, so that the VA's early-return codepath is actually exercised.
This PR will be followed by a non-test PR which removes this
early-return codepath and modifies this test further, but I thought it
was important to have this test in fully working order before modifying
the code it tests.
Part of https://github.com/letsencrypt/boulder/issues/7809
dd566a959c