nwg-panel: fix cross-compiled result to not ship build-time dependencies

hosts/common/programs/nwg-panel/default.nix

@@ -62,6 +62,8 @@ in
       ];
       # XXX(2024/06/13) the bluetooth stuff doesn't cross compile, so disable it
       propagatedBuildInputs = lib.filter (p: p.pname != "pybluez") base.propagatedBuildInputs;
+
+      strictDeps = true;
     });
 
     # fs.".config/nwg-panel/config".symlink.target = ./config;