statshost: deprecate InfluxDB for long-term metrics storage, add options to
disable InfluxDB or just reading/writing from/to InfluxDB for a phase-out
period. InfluxDB consumes a lot of RAM, increasing with the number of
metrics and distinct label values. Prometheus got much better in storing
data for a longer time period while being far better at memory consumption.
Prometheus stores data for at least 10 weeks by default, which can
extended. InfluxDB will be removed completely with the 22.11 platform
version (#PL-131027).
fc-postgresql upgrade: use fast cloning mode of pg_upgrade (using XFS
reflinks) if possible; fix --no-existing-db-check option (#PL-131056).