ipynb: remove the add_parsed_event() hack in the UseCaseExamples notebook

Created by: JaviMerino

The bart check of util estimation in the UseCaseExamples_SchedTuneAnalysis notebook starts with code to add the sched_boost_task event filtered by comm back to the trappy FTrace object which is a hack. This is needed because trappy's grammar module couldn't do it when the notebook was originally written. trappy learned to apply filters in its Parser() object in version 5.7.0, which led to the simplification of the similar SchedTune test in b9d488f5 ("tests: simplify stune's boosted utilization signal test").

Apply a similar change to the UseCaseExamples_SchedTuneAnalysis ipython notebook. This way the test is simpler and we educate our users on the ability to use filters with the Analyzer ❤