fix: reschedule nightly and optimize canary runs

[Shubhranshu153]

Problem

1. Nightly builds were scheduled at 9:00 UTC which conflicted with patch reboot times
2. Deb Canary workflow was running every 10 minutes, creating 144 workflow runs per day and flooding the GitHub Actions page

Solution

1. Reschedule Nightly Builds to 6 AM PST (14:00 UTC)

All nightly builds have been moved to 6 AM PST to avoid conflicts with patch reboot windows.

2. Optimize Deb Canary Workflow

Restructured the canary workflow to run hourly while maintaining the same monitoring frequency:

• I've reviewed the guidance in CONTRIBUTING.md

License Acceptance

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[Swapnanil-Gupta]

Is it a good idea to block this runner for 55-60 minutes when most of that time is spent sleeping?

[Shubhranshu153]

not really so the other case you are spinning up a runner every 5 mins and it runs for 3 mins and stops. if its a cold start then that is expensive.

[Shubhranshu153]

Actually yes the runners are running for only ~10-15 seconds, in that case this can be worse. i will look what other options are there

[sondavidb]

Part of the reason for splitting the canary into a separate shellscript was so that we can easily run it on a local machine if we wanted to.

I would prefer if we keep singular canary runs within a singular script. Then call the script multiple times from either a separate bash file or within GitHub. (Or even a Go file?)

[Shubhranshu153]

we can do that or have an option to control it.

[sondavidb]

I'm also okay with that. But I would like the option to do so easily before approving.