Remove legacy job options from TGC_Digitization package

Removing one legacy job options file and the corresponding reference in the package CMakeLists.txt file.

MuonSpectrometer/MuonDigitization/TGC_Digitization/share/TGC_Digitization_jobOptions.py

-from AthenaCommon.AlgSequence import AlgSequence
-job = AlgSequence()
-
-from AthenaCommon import CfgGetter
-from Digitization.DigitizationFlags import jobproperties
-if jobproperties.Digitization.doXingByXingPileUp(): # PileUpTool approach 
-    job.PileUpToolsAlg.PileUpTools += [ CfgGetter.getPrivateTool("TgcDigitizationTool", checkType=True) ]
-else : # Algorithm approach
-    job += CfgGetter.getAlgorithm("TGCDigitizer", tryDefaultConfigurable=True)