[fast/warm-reboot] Fix timers query (sonic-net#4022)

- What I did
Fixed an issue that timers weren't stopped upon warm or fast-reboot. This is because sonic-delayed.target was removed but this script was not updated.

- How I did it
Fetch timers associated with sonic.target

- How to verify it
fast-reboot:

...
Thu Aug 7 05:41:03 PM IDT 2025 Stopping aaastatsd.timer ...
Thu Aug 7 05:41:03 PM IDT 2025 Stopped aaastatsd.timer ...
Thu Aug 7 05:41:03 PM IDT 2025 Stopping featured.timer ...
Thu Aug 7 05:41:03 PM IDT 2025 Stopped featured.timer ...
Thu Aug 7 05:41:03 PM IDT 2025 Stopping hostcfgd.timer ...
Thu Aug 7 05:41:03 PM IDT 2025 Stopped hostcfgd.timer ...
Thu Aug 7 05:41:03 PM IDT 2025 Stopping tacacs-config.timer ...
Thu Aug 7 05:41:03 PM IDT 2025 Stopped tacacs-config.timer ...
...

Signed-off-by: Stepan Blyschak <stepanb@nvidia.com>

Author: stepanblyschak

scripts/fast-reboot

@@ -865,7 +865,7 @@ if [ -x ${LOG_SSD_HEALTH} ]; then
 fi
 
 # Stop any timers to prevent any containers starting in the middle of the process.
-TIMERS=$(systemctl list-dependencies --plain sonic-delayed.target | sed 1d)
+TIMERS=$(systemctl list-dependencies --plain sonic.target | sed 1d | grep '.timer$')
 for timer in ${TIMERS}; do
     debug "Stopping ${timer} ..."
     systemctl stop ${timer}