As reported by @maniteja123

y_true = [0, 1]
weights = [1, 1]
_weighted_percentile(y_true, weights, 50)
0

Do we want to do some sort of linear interpolation as described in this method?
https://en.wikipedia.org/wiki/Percentile#The_Weighted_Percentile_method