Dropped usage of IOHelper by converting a number of tests to PyConf

A few tests have been disabled as part of this MR, namely :

• Moore.test_lbexec_hlt2_pp_2022_reprocessing_data
• Moore.test_lbexec_hlt2_pp_2022_reprocessing_data_check
• Moore.test_lbexec_hlt2_pp_2022_reprocessing_data_check_output The reason for this disabling is that these tests are failing for long, although these failures were not visible so far and were only revealed with this MR.

Another set has been dropped :

• Hlt2Conf.hlt2_SMOG2_thor_data_2022_HLT2rerun
• Hlt2Conf.hlt2_SMOG2_thor_data_2022_HLT2rerun_check_output

In details, it's 2 sets of tests where each time the first one reprocesses some HLT2 data and the last one checks something. Except the reprocessing does not produce any data at all anymore. This went unnoticed until this MR moved the tests to PyConf which now complains.

An issue (#878) has been opened for the first set to be revived. The second set was felt to not be useful anymore (see discussion in the issue)