The time displayed in DHCP v4/v6 server lease op-mode commands does not honor system timezone and forces UTC TZ.

This creates inconsistency with timestamps in log records (any journalctl output processed via show log dhcp/dhcpv6 server ... or monitor log dhcp/dhcpv6 server ...) leading to unnecessary one-off re-transformation overhead for monitoring and troubleshooting.

This was implemented as part of T6998 to fix timestamp rendering in modern Python. The implementation discussion does not capture the reasoning behind forcing UTC TZ.