Fix args' clash in CTest; it fixes ATEAM-1075 and ATLASG-2905

This MR implements the suggestion by @maszyman in ATEAM-1075 to avoid the name clash between args in the CTest PyJobTransforms_trfSignatures_ctest reported in ATLASG-2905 and followed up in ATEAM-1075 :

makeTrfJSONSignatures.py: error: ambiguous option: --output could match --outputFileValidation, --outputNTUP_PHYSVAL_MRGFile

The option allow_abbrev=False avoids the abbreviation and thus the error:

Closes ATEAM-1075

Closes ATLASG-2905

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Cc: @rhammad @turra @tsulaia