2536b7dee4
The 'Filter' F-Curve modifier type was never actually implemented, so it's now properly removed from the code. The enum entry `FMODIFIER_TYPE_FILTER` in `DNA_anim_types.h` is kept, so that it's clear that this once existed (which explains what would otherwise be a hole in the values of the enum entries). No functional changes. Pull Request: https://projects.blender.org/blender/blender/pulls/123906