gns3-gui: Add the missing setuptools dependency

Fixes #81048.
Note: This commit is not cherry-picked, but required to fix:
ImportError: No module named pkg_resources

pkgs/applications/networking/gns3/gui.nix

@@ -19,7 +19,7 @@ in pythonPackages.buildPythonPackage rec {
   propagatedBuildInputs = with pythonPackages; [
     raven psutil jsonschema # tox for check
     # Runtime dependencies
-    sip (pyqt5.override { withWebSockets = true; })
+    sip (pyqt5.override { withWebSockets = true; }) setuptools
   ] ++ stdenv.lib.optional (!stable) pythonPackages.distro;
 
   doCheck = false; # Failing