Description

This PR replaces chrono with jiff. This leads to better support for strftime formatters related to timezones, and e.g. in the aws module the API is a bit more ergonomic.

Note: The output of formatted time strings is different in some cases, but still within POSIX rule margins.

This PR also includes #4269:

Instead of a static offset, also allow specifying timezones with their IANA time zone database names (Europe/Berlin) in the time module utc_time_offset option. This can help avoid issues around daylight saving time.

Motivation and Context

Related #4173
Closes #6621

Screenshots (if appropriate):

How Has This Been Tested?

• I have tested using MacOS
• I have tested using Linux
• I have tested using Windows

Checklist:

• I have updated the documentation accordingly.
• I have updated the tests accordingly.