9024 workflow test serverless function follow up (#9066)

-  Fix Tablist style
- Fix dropdown style (wrong grey background)
- Update dropdown variable when no outputSchema is available 



https://github.com/user-attachments/assets/56698fe8-8dd3-404a-b2b2-f1eca6f5fa28

packages/twenty-server/src/modules/workflow/common/workspace-services/workflow-version-step.workspace-service.ts

@@ -81,6 +81,15 @@ export class WorkflowVersionStepWorkspaceService {
           valid: false,
           settings: {
             ...BASE_STEP_DEFINITION,
+            outputSchema: {
+              link: {
+                isLeaf: true,
+                icon: 'IconVariable',
+                tab: 'test',
+                label: 'Generate Function Input',
+              },
+              _outputSchemaType: 'LINK',
+            },
             input: {
               serverlessFunctionId: newServerlessFunction.id,
               serverlessFunctionVersion: 'draft',