Remove `Material > Shadow Mode` and use `Object > Shadow Ray Visibility`
and `Material > Transparent Shadows` instead.
The versioning system auto-updates objects/materials in EEVEE
scenes so their behavior is as close as possible to the previous one.
Update Cycles to use the native `use_transparent_shadow` property.
Note:
Material changes don't set any `recalc` flag on the objects that use
them, so the EEVEE Next shadow maps don't update when changing
settings/nodes.
Fixing this issue is required for 4.1, but it's out of the scope of this PR.
Pull Request: https://projects.blender.org/blender/blender/pulls/113980