tests/eas/acceptance: increase accuracy of little cpus test in the Offload Migration testcase
Created by: JaviMerino
The window for test_little_cpus_run_tasks()
was loosely defined as just the migrator delay, which doesn't take into account the time it takes for rt-app to spawn and create its tasks. After fa4bce73 ("tests/eas/acceptance: Increase required busy time for idle pull test"), the test is more strict, so increase the accuracy of the window to meet the new restrictions.