feat: propagate errors up subgraphs and show slot errors in subgraphs (#6963)

https://github.com/user-attachments/assets/6531879d-a8a2-420a-aaca-ee329386dd1a

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6963-feat-propagate-errors-up-subgraphs-and-show-slot-errors-in-subgraphs-2b76d73d3650813e8391fac0a5e6dc9b)
by [Unito](https://www.unito.io)

---------

Co-authored-by: github-actions <github-actions@github.com>

src/services/litegraphService.ts

@@ -119,11 +119,6 @@ export const useLitegraphService = () => {
         return { color: '#0f0' }
       }
     }
-    node.strokeStyles['nodeError'] = function (this: LGraphNode) {
-      if (app.lastNodeErrors?.[this.id]?.errors) {
-        return { color: 'red' }
-      }
-    }
     node.strokeStyles['dragOver'] = function (this: LGraphNode) {
       if (app.dragOverNode?.id == this.id) {
         return { color: 'dodgerblue' }