Allow unauthenticated access to /metrics for Prometheus scraping

Allow unauthenticated access to /metrics for Prometheus scraping: a task in MiMo-V2.6-RL-harbor-code: MiMo-V2.6-RL Code (Harbor) (Harbor dataset). I'm running Drone behind a private network and would like our internal Prometheus instance to scrape the /metrics endpoint exposed by drone-server.