Update updated_at when saving TI to DB

[gyli]

fixes: #40623

Tested with query

select start_date, end_date, updated_at from task_instance where task_id = 'sleep' ORDER BY start_date DESC;

The lower result is the initial test with example provided in the issue (sleep time is reduced from 50 to 5), showing updated_at is before end_date.
The upper result is the log after this fix, showing updated_at is now after end_date.

I have also tried flag_modified, while it does not work at the same place.

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[gyli]

Hi @shahar1 and @romsharon98, could you help me unblock the failed check here? Does it matter for merging PR?
The failed unit tests seem unrelated to my change, and they both pass on my local when I do breeze shell --force-lowest-dependencies and then pytest tests/triggers/test_external_task.py.

[shahar1]

Hi @shahar1 and @romsharon98, could you help me unblock the failed check here? Does it matter for merging PR? The failed unit tests seem unrelated to my change, and they both pass on my local when I do breeze shell --force-lowest-dependencies and then pytest tests/triggers/test_external_task.py.

I apologize as it seems like I've missed your last message.
I think that we're good to go :)