vars: refactor - remove create_machine_vars_interactive in favor of run_generators

The motivation is to create one powerful entrypoint shared by the GUI as well as the CLI in order to not having to maintain too much separate code paths.

As a next step, generate_vars can probably also be removed.

pkgs/clan-app/ui/src/workflows/Install/steps/installSteps.tsx

@@ -550,7 +550,7 @@ const InstallSummary = () => {
     }
 
     const runGenerators = client.fetch("run_generators", {
-      all_prompt_values: store.install.promptValues,
+      prompt_values: store.install.promptValues,
       machine: {
         name: store.install.machineName,
         flake: {