Blender Git Loki

Alembic: remove non-functional "Renderable Objects" only option

When introduced in {rB61050f75b13e} this was actually working (meaning
it checked the Outliner OB_RESTRICT_RENDER flag and skipped the object if
desired).

Behavior has since then been commented in rBae6e9401abb7 and apparently
refactored out in rB2917df21adc8.

If checked, it seemed to be working (objects marked non-renderable in
the Outliner were pruned from the export), however unchecking that
option did not include them in the export.

Now it changed - for the worse if you like - in rBa95f86359673 which
made it so if "Renderable Objects" only is checked, it will still export
objects invisible in renders. So since we now have the non-functional
option with a broken/misleading default, it is better to just remove it
entirely.

In fact it has been superseeded by the "Visible Objects" option (this
does the same thing: depsgraph is evaluated in render mode) and as a
second step (and to make this even clearer) a choice whether
Render or Viewport evaluation is used can be added (just like the USD
exporter has). When that choice is explicit, it's also clear which
visibility actually matters.

This is breaking API usage, should be in release notes.

ref. T89594

Maniphest Tasks: T89594

Differential Revision: https://developer.blender.org/D11808