Fix cron parsing for Daylight Savings

When a system is configured with a time zone that observes Daylight Savings and a cron schedule is configured for any time after November 1, 2020, an Error 500 page will be generated due to TZInfo::AmbiguousTime:

Fugit::Cron.new('7 12 1 10 *').next_time(Time.now)
Traceback (most recent call last):
        1: from (irb):238
TZInfo::AmbiguousTime (Time: 2020-11-01 01:00:00 UTC is an ambiguous local time.)

This is due to a long-standing bug in Chronic: https://github.com/mojombo/chronic/issues/147.

Replace chronic with gitlab-chronic v0.10.3 to bring in the fix for Daylight Savings parsing: https://gitlab.com/gitlab-org/gitlab-chronic/merge_requests/3.

Also upgrade gitlab_chronic_duration to v0.10.6.2 to fix numerizer dependency.

Closes #37014 (closed)