Prior to this commit, the Fade Inactive Geometry overlay would inspect
the active object and compare each other object's mode and hide them if
they did not share the same mode.
This was incorrect in the following case:
* If multiple objects were all in similar modes, as can be the case
with "Lock Object Modes" off, or with multi-edit mode, then objects
would remain unfaded if they shared the same mode as the active
object.
To fix this, we explicitly check for both the active and the "other"
object being in edit mode and avoid fading in this case.
Ref: #87704
Pull Request: https://projects.blender.org/blender/blender/pulls/132255
a4a0c81cd6