I don't do this often, but it seems the quickest way is to disable area light > "visible on specular", and set general visibility = 0.0
This will prevent specular from that light appearing on other surfaces though, as you can see in the glossy sphere below.
The other option is to set the area light > light pass ID = 2 and general visibility = 0.0. Then put all your glass in a new mesh, and disable that mesh's octane vtab > light pass mask > light pass ID 2
I have attached a zip with both examples