Export deforming bones only without exporting animations

Currently, to export deformation bones only, you have to export animations:
I need to separately export meshes without animations, and animations attached to the armature; however, I need the skeleton to always be exported without non-deforming bones.

No files, tests, or entry points are identified in the issue. First determine which exporter or tool the request targets and clarify the expected behavior for meshes, animations, and deforming versus non-deforming bones before locating the relevant implementation and tests.

Written by the indexing model from the issue text.