Before #12850, we will only try to shrink the dict in serverCron,
which we can control by using a child process, but now every time
we delete a key, the shrink check will be called.
In these test (added in #12802), we meant to disable the resizing,
but druing the delete, the dict will meet the force shrink, like
2 / 128 = 0.015 < 0.2, the delete will trigger a force resize and
will cause the test to fail.
In this commit, we try to keep the load factor at 3 / 128 = 0.023,
that is, do not meet the force shrink.
29e6245a05