chore: Disable rhh metrics, as they aren't typically observed

[philjb]

rhh hit metrics are expensive to bookkeep: they have a default 10% sample rate which is high and use a global random source which serializes access to do that sampling. They are rarely examined so we can disable them.

switch this to false:

influxdb/pkg/rhh/rhh.go

Line 430 in 94dbbdc

MetricsEnabled: true,