Add loose reference run He/D2 sequence

This MR adds a sequence for pHe/pD2 data taking during the reference run with a looser SMOG2 minimum bias prescale. The loosening of the SMOG2 prescale will let us reach our targeted yields in half the running time and will not affect the overall data volume of the MB sample. In addition, the prescale for the SMOG2 luminosity line is removed in the new sequence. The resulting change in trigger rate is expected to be less than 1 kHz (estimated from monet), and the overall increase in data volume is expected to be O(1 TB).