[fast/warm-reboot] Fix timers query

[stepanblyschak]

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 ...
...

Previous command output (if the output of a command-line utility has changed)

New command output (if the output of a command-line utility has changed)

[mssonicbld]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[vaibhavhd]

Thank you for finding and fixing this. I am curious to know how this was detected, and if something actually failed functionally?

[vaibhavhd]

So there may be other places where timer service is still used and not removed/updated. We should do full code parsing to find these issues.
One example that I could easily discover - tacacs service definition - https://github.com/sonic-net/sonic-buildimage/blob/fcd6eb368f3b1f1bf4e1d6276f0314e9ec25c2ee/files/build_templates/tacacs-config.timer#L12C1-L12C57

CC - @StormLiangMS , @yejianquan

[stepanblyschak]

@vaibhavhd We encountered similar issue in config reload where soon after boot if we run config reload timers could expire in the middle of config reload. Very similar issue that was addressed in this code block in warm-reboot. This has been fixed by #4021.

I started looking for places where sonic-delayed is used and the place you mentioned is addressed by sonic-net/sonic-buildimage#23630