Start using next step ids (#11683)

- update workflow executor
- update next step ids on step creation/deletion
- use these in workflow run
- use these in variables

packages/twenty-front/src/modules/workflow/validation-schemas/workflowSchema.ts

@@ -21,6 +21,7 @@ export const baseWorkflowActionSchema = z.object({
   id: z.string(),
   name: z.string(),
   valid: z.boolean(),
+  nextStepIds: z.array(z.string()).optional().nullable(),
 });
 
 export const baseTriggerSchema = z.object({