Fix ZeroDivisionError in simple_efficiency when load_loss=0#2646

aman-coder03 wants to merge 2 commits intopvlib:mainpvlib/pvlib-python:mainfrom

aman-coder03:fix/simple-efficiency-zero-load-lossaman-coder03/pvlib-python:fix/simple-efficiency-zero-load-lossCopy head branch name to clipboard