Bone gizmos fail to refresh when multiple objects selected and you shwitch modes

[keianhzo]

Description
When multiple object are selected and the active object is a bone with a gizmo, we fail to refresh the bone gizmos as we assume that all select objects are bones.

To Reproduce
Steps to reproduce the behavior:

• Add an armature and add a component with a gizmo
• Add a mesh
• Select the mesh, then the armature
• Switch to edit mode

Expected behavior
All gizmos should be correctly refreshed

Additional context

Traceback (most recent call last):
  File "io_hubs_addon/components/gizmos.py", line 190, in depsgraph_update_post
    if len(ob.data.edit_bones) != ob.data.hubs_old_bones_length:
AttributeError: 'Mesh' object has no attribute 'edit_bones'