One of the fundamental characteristics of Dynamic Lighting is that light sources multiply. I'm not sure there's a way around that. It might be possible to approximate by messing around with the light multiplyer [sic], but I suspect that the results would not match the PF rule requirements. Here is my suggestion: It's clunky, but if PF familiars act like 5e Familiars, it should do the job. Normally, wizards cannot see through both their own and their familiar's eyes at once. Whenever the wizard player wants to use their familiar's sight, have them move their own token to the familiar's spot temporarily. Alternatively, keep a regular token for the familiar for the player to move, and place a sighted familiar copy back at some unimportant part of the map or perhaps behind regular fog of war or in a slightly larger than 1 square block of dynamic lighting walls. Whenever the player wants to look through the familiar's eyes, the GM can simply move the sighted token to the familiar's spot, then back again when the sight sharing is over. I suggest the DM move it, since the DM can ignore the travel blocking nature of DL walls. Naturally, the page would need to be set to update on drop, or some parts of the map might be unintentionally revealed. This would be very easy to automate with the API and token mod, but that's the best I can come up with, without.
