Allow setting time zone for cron jobs

[adamcstephens]

Clear and concise description of the problem

As a user of cron jobs, I would like to have a consistent local time that my jobs are run. Currently cron jobs are set in UTC but my time zone like many others has a daylight saving time change. This means that the time I configure a cron job for now, will be an hour different during ~half the year.

Suggested solution

The user facing changes for this could be a configuration option for administrators to set the time zone for cron jobs, or the ability to set the time zone when configuring a cron job.

Alternative

I've considered manually changing all the cron jobs twice a year, but this is tedious and error prone.

Additional context

No response

Validations

• Checked that the feature isn't part of the next version already [https://woodpecker-ci.org/faq#which-version-of-woodpecker-should-i-use]
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.

[6543]

woodpecker/server/cron/cron.go

Line 71 in cfdb32a

// TODO: allow the users / the admin to set a specific timezone

[plague-doctor]

Can we have the local time for cron? Fiddling with UTC is... unpleasant.