Who is the protagonist and antagonist in "Looking for a Rain God" and why?

There isn't one particular protagonist or one particular antagonist in this story. The people in the bush collectively play the role of the protagonist, and the gods collectively play the role of the antagonist.
The people are desperate for rain. They live off the land but have endured a drought for seven years. They live in hope that the rain will come but it never does, and the longer the drought lasts, the more desperate they become. The people live in "a desolation of suffering and deprivation and sorrow." They pray to the gods, but the gods remain unsympathetic or indifferent. The rain-god seems out of reach, and "the god of Christianity is uninterested."
Eventually, one family becomes so desperate that they decide to sacrifice two little girls to some obscure rain-god. The girls are sacrificed, but the obscure rain-god remains as indifferent as the others. The rain still does not fall, and instead, there is only "a deathly silence at night and the devouring heat of the sun by day."
At the end of the story, the author poses a question. She asks,

Is the new rain-god knowledge, progress and machines, and if so, how and when is this to be communicated to people who have courage but little education?

This question suggests that perhaps the real antagonist of the story is the ignorance of the people. The gods they pray to are merely symptoms or manifestations of that ignorance.