EarlyStopping is based upon callback.on train epoch end, not callback.on validation epoch end

EarlyStopping is based upon callback.on train epoch end, not callback.on validation epoch end: a task in MiMo-V2.6-RL-oss: Agentic RL Environments (MiMo RL release). 🐛 Bug EarlyStopping patience is supposed to be based upon callback.on validation epoch end. "It must be noted that the patience…