nix: keep shell names simple

flake.nix

@@ -104,6 +104,11 @@
               packages.python-scripts
             ];
           };
+          py-scripts = pkgs.mkShell {
+            buildInputs = [
+              packages.python-scripts
+            ];
+          };
           analyze-m100-agg-power = pkgs.mkShell {
             buildInputs = [
               pkgs.R