Caused by using due instead of original_due when card was in learning.
I think the original goal of that code was to ignore the learning timestamp
and show the next review date instead, but it's both simpler and more
intuitive to show the learning date instead.
* Remove v1/v2 support from deck list
* Remove v1/v2 support from most routines and show error
* Remove scheduler_version from preferences
* Fix formatting
* Remove v1/v2 conditionals from Python code
* Fix legacy importer
* Remove legacy hooks
* Add missing scheduler checks
* Remove V2 logic from deck options screen
* Remove the review_did_undo hook
* Restore ability to open old options with shift (dae)
* Remove deprecated `and_hms()`
* Update chrono
* Update licenses and fix script
* Remove deprecated Date struct
* Remove chrono pin
* Skip format check on .vscode
Was failing for no reason.
* Replace deprecated chrono functions
* Add cargo-deny to update-licenses & pin versions (dae)
* Remove time 0.1 dependency (dae)
We don't need to wait for chrono 0.5; it was provided behind a legacy
feature flag.