Fix timeline "new year" bug

[ericboucher]

Description

This fixes #1411.

I made two small changes to fix the issue:

• add a buffer of one so that we can use the increment to switch between years
• revert to using the full availableDates array for the final update function

Unrelated, this PR also fixes a small bug in the Python API CI by fixing the Python version.

How to test the feature:

• [ ]
• [ ]

Checklist - did you ...

Test your changes with

• REACT_APP_COUNTRY=rbd yarn start
• REACT_APP_COUNTRY=cambodia yarn start
• REACT_APP_COUNTRY=mozambique yarn start
• Add / update necessary tests?
• Add / update outdated documentation?

Screenshot/video of feature:

[github-actions]

Build succeeded and deployed at https://prism-1412.surge.sh
(hash 2a49cf2 deployed at 2025-01-15T22:45:11)

[wadhwamatic]

looks good from my side @ericboucher, thanks. Did you intend to keep the console logs?

[gislawill]

Just ran through the paces with seasonal CDI paired with various wms layers — all the logic worked well. Nice work @ericboucher