Doesn't impact Ente's production instances since this endpoint was disallowed on
the load balancer, but instead of requiring the same for folks who are self
hosting we modify the source to not expose /metrics on :8080 (they'll still be
available on :2112).
Refs:
- 2199a42d96/middleware.go (L345)
- https://github.com/ente-io/ente/discussions/2562