Schedules must be defined in UTC not OTRSTimeZone

[pboguslawski]

Proposed change

Znuny cron schedules (i.e. defined in Generic agent jobs or Daemon::SchedulerCronTaskManager::Task parameters) after dc8282e00d72b87d1ca39a9559c0e63a0176810b are UTC schedules not OTRSTimeZone schedules (not elegant but probably better leave this solution now to avoid daylight savings quirks).

This mod fixes/adds schedule descriptions to explain this.

Type of change

• '1 - 🐞 bug 🐞' - Bugfix (non-breaking change which fixes an issue)

Additional information

Replaces: https://github.com/znuny/Znuny/pull/124 Fixes: dc8282e00d72b87d1ca39a9559c0e63a0176810b Author-Change-Id: IB#1110542

Checklist

• [x] The code change is tested and works locally.(❗)
• [x] There is no commented out code in this PR.(❕)
• [ ] You improved or added new unit tests.(❕)
• [x] Local ZnunyCodePolicy passed.(❕)
• [x] Local UnitTests / Selenium passed.(❕)
• [ ] GitHub workflow CI (UnitTests / Selenium) passed.(❗)

[rkaldung]

@pboguslawski We will add to the documentation where within Znuny which time zone applies. We have an internal issue for this. Thank you for the contribution, but we prefer the documentation for this topic.