To-do list for discontinuing 8.x.x support

[dhalbert]

Edit this as needed.

Before release:

• Update frozen modules (again).

Immediately after release:

• Create 9.0.x branch.
• Merge Show /sd/ directory circuitpython/CircuitPython_Library_Screenshot_Maker#16. Adds /sd and settings.toml to library screenshots.
• Activate version 9.0.x on ReadTheDocs. The latest semver version automatically becomes the stable release on ReadTheDocs.

When 8.x is no longer supported:

• Stop building 8.x.x library bundles, by changing https://github.com/adafruit/circuitpython-build-tools/blob/main/circuitpython_build_tools/target_versions.py
• Add last 8.x bundle to https://learn.adafruit.com/welcome-to-circuitpython/frequently-asked-questions#faq-3105289.
• Update bundles list at https://circuitpython.org/libraries .
• Update circup to not download 8.x bundles

[vladak]

Nice issue number :-) (sorry, could not resist)