Set memory requirement for memory intensive ART tests

The affected tests in Digitization and ISF_Validation ART packages consume more than 3.2 GB of memory, which puts them at risk of failing if they get sent to TRIUMF. Sometimes they fail on 1st attempt and pass on the 2nd, which still is not good as it consumes CPU and delay the test results. This MR introduce ART-memory requirements, tunes according to the max RSS reported in last night results.

Should fix ATLASSIM-7190