Make the JUnit report reflect every Cucumber result status (and stop leaking state)

Make the JUnit report reflect every Cucumber result status (and stop leaking state): a task in MiMo-V2.6-RL-oss: Agentic RL Environments (MiMo RL release). Our plugin turns Cucumber's JSON output into a JUnit XML report so CI servers can consume the results. The JUnit generator takes the parsed…