add permitted insecure packages

Signed-off-by: Matthew Stobbs <matthew@sprouting.cloud>

flake.nix

@@ -31,6 +31,7 @@
         config = {
           allowUnfree = true;
           allowUnfreePredicate = _: true;
+          permittedInsecurePackages = [ "electron-39.8.10" ];
         };
       };
       stateVersion = "26.05";