Issue 6258 - Add sleep for ramdom failure in two tests

[mmatsuya]

Bug Description: The following test fails frequently. In the first one, the access log is checked before it's written. In the second one, multiple threads with the same file descriptor for access log file writes the logs with out of order.

dirsrvtests/tests/suites/healthcheck/health_config_test.py::test_healthcheck_notes_unindexed_search dirsrvtests/tests/suites/paged_results/paged_results_test.py::test_multi_suffix_search

Fix Description: Adding sleep mitigates the failure.

Fixes: #6258

(cherry-picked from the commit 1bd2e6e)

[vashirov]

We have a stress test that runs pages search 1000 times:

389-ds-base/dirsrvtests/tests/suites/paged_results/paged_results_test.py

Lines 1258 to 1268 in a3d3521

	abandon_rate = 10
	page_size = 500
	nbloops = 1000
	search_flt = r'(uid=*)'
	searchreq_attrlist = ['dn', 'sn']
	log.info('Set user bind %s ' % create_user)
	conn = create_user.bind(TEST_USER_PWD)
	for idx in range(nbloops):
	req_ctrl = SimplePagedResultsControl(True, size=page_size, cookie='')
	# If the issue #5984 is not fixed the server crashs and the paged search fails with ldap.SERVER_DOWN exception
	paged_search(conn, create_40k_users.suffix, [req_ctrl], search_flt, searchreq_attrlist, abandon_rate=abandon_rate)

Usually it takes about 300 seconds to complete, but with this change it takes significantly larger amount of time. I don't think we should do it here.

[mmatsuya]

I thought that the sleep time can be shorter.
In my test, it worked even with time.sleep(.1) for rhel9.2 and rhel9.5. It may depend on the test environment, though.