Reverted broken CustomAttribute test, replaced f-strings with formats (#7501)
Reverted broken CustomAttribute test, replaced f-strings with formats (#7501)

htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor,htcondor/htcondor