stop using schedd.transaction in PostJob

[belforte]

it has been deprecated

need to change this code

CRABServer/src/python/TaskWorker/Actions/PostJob.py

Lines 2912 to 2920 in 7f4e9ee

	with self.schedd.transaction(htcondor.TransactionFlags.NonDurable):
	for param in params:
	self.schedd.edit([self.dag_jobid], param, str(params[param]))
	self.schedd.edit([self.dag_jobid], 'CRAB_PostJobLastUpdate', str(time.time()))
	# Once ClassAd state attributes have been updated, let HTCondor remove the job from the queue
	self.schedd.edit([self.dag_jobid], "LeaveJobInQueue", classad.ExprTree("false"))
	self.logger.info(" -----> Finished %s -----", msg)
	self.logger.info("====== Finished to update job ClassAd.")
	break

[belforte]

schedd.transaction was introduced in 48b3700
but there is no record of the reason for this choice. I suspect that we can simply remove it