update mc21a ART tests to mc23a
As the title says, it should be straightforward unless I have made some typo somewhere...
Two of the tests are doing a regression test against a reference file, so the old files should be removed from /eos/atlas/atlascerngroupdisk/data-art/grid-input and the new ones added (the names have changed since they contained "mc21a"). Should I ask write permissions for grid-input or should let someone else (@zhubacek I guess) to do it ?
cheers, Tommaso