Upgrade to robfig/cron/v3 to support time zone specification

[kaovilai]

Breaking change (can be mitigated if needed in the future): v1 branch accepted an optional seconds field at the beginning of the cron spec. This is non-standard and has led to a lot of confusion. The new default parser conforms to the standard as described by the Cron wikipedia page.. It is unlikely that this affects us per #31

Other notes:

CRON_TZ is now the recommended way to specify the timezone of a single schedule, which is sanctioned by the specification. The legacy "TZ=" prefix will continue to be supported since it is unambiguous and easy to do so.

References: https://pkg.go.dev/github.com/robfig/cron/v3#readme-upgrading-to-v3-june-2019
Signed-off-by: Tiger Kaovilai [email protected]

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Does your change fix a particular issue?

Fixes #7792

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• Accepted the DCO. Commits without the DCO will delay acceptance.
• Created a changelog file or added /kind changelog-not-required as a comment on this pull request.
• Updated the corresponding documentation in site/content/docs/main.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 58.67%. Comparing base (27392d3) to head (160a2e1).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #7793   +/-   ##
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  Coverage   58.66%   58.67%           
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  Files         345      345           
  Lines       28733    28739    +6     
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+ Hits        16856    16862    +6     
  Misses      10448    10448           
  Partials     1429     1429           

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[blackpiglet]

Please check the failed cases in the CI action.

[kaovilai]

It's not failing locally...

[kaovilai]

@blackpiglet looks like it was a flaky test

[blackpiglet]

Thanks.
Is this PR target for the v1.14.0 RC?
If not, how about revisiting this PR after the release-1.14 branch cut?

[kaovilai]

Is this PR target for the v1.14.0 RC?
If not, how about revisiting this PR after the release-1.14 branch cut?

Sounds good.

[kaovilai]

Not 1.14 target

[reasonerjt]

Thanks @kaovilai
It would be great to make update to the doc to add an example for the more advanced format:
https://velero.io/docs/v1.14/backup-reference/#schedule-a-backup

But this is optional since it's briefly covered in the Wikipedia link