RSS of single-node non-gimlet deployment got stuck trying to time sync

I tried to deploy current main on dunkin, a helios lab machine (dfb6853f).

At first, I hit issues due to chrony not being installed (#4094), but I installed that package, then restarted the baseline service.

After a few laps with trying to stand up omicron (including running an uninstall command from omicron-package and running the destroy virtual hw script between laps), sled agent is stuck trying to timesync.

These are the zones that came up:

global
sidecar_softnpu
oxz_switch
oxz_internal_dns_f8491614-6fd1-40f5-88c7-6d433054ec43
oxz_internal_dns_9295a7fc-6942-4ee6-98dc-803429a63d98
oxz_internal_dns_7e1a3d47-8086-45a6-b88d-3700f8b9cff7
oxz_ntp_517cf03b-7086-4a1c-b6e7-0054588608ab

The ntp zone thinks the clock is well synced:

root@oxz_ntp_517cf03b-7086-4a1c-b6e7-0054588608ab:~# dladm
LINK        CLASS     MTU    STATE    BRIDGE     OVER
vopte0      vnic      1500   up       --         ?
oxControlService4 vnic 9000  up       --         ?
root@oxz_ntp_517cf03b-7086-4a1c-b6e7-0054588608ab:~# chronyc tracking
Reference ID    : 7F7F0101 ()
Stratum         : 10
Ref time (UTC)  : Mon Sep 25 15:05:11 2023
System time     : 0.000000000 seconds fast of NTP time
Last offset     : +0.000000000 seconds
RMS offset      : 0.000000000 seconds
Frequency       : 0.117 ppm fast
Residual freq   : +0.000 ppm
Skew            : 0.000 ppm
Root delay      : 0.000000000 seconds
Root dispersion : 0.000000000 seconds
Update interval : 0.0 seconds
Leap status     : Normal

On the sled agent side, I see:

15:05:12.485Z INFO SledAgent (RSS): Timesync for [fd00:1122:3344:101::1]:12345 TimeSync { sync: false, ref_id: 2139029761, ip_addr: ::, stratum: 10, r
ef_time: 1695654311.4054208, correction: 0.0 }                                                                                                        
    file = sled-agent/src/rack_setup/service.rs:476                                                                                                   
15:05:12.485Z WARN SledAgent (RSS): Time is not yet synchronized           
    error = "Time is synchronized on 0/1 sleds"  

Start at sled-agent/src/rack_setup/service.rs:476 and compare the sled agent's Timesync result with the chronyc tracking output from the NTP zone. Reproduce the single-node RSS deployment on dunkin if available; done means the sled agent no longer remains stuck reporting that time is not synchronized.