spec: Add missing lxml as Requires
spec: Add missing lxml as Requires

RedHat-Eng-PGM/python-schedules-tools,RedHat-Eng-PGM/schedules-tools,RedHat-Eng-PGM/schedules-tools,RedHat-Eng-PGM/python-schedules-tools,RedHat-Eng-PGM/python-schedules-tools,RedHat-Eng-PGM/schedules-tools