Update edu.json

Author: adamfowlerit

_data/portals/edu.json

@@ -65,17 +65,7 @@
         "portalName": "AI Skills for Educators",
         "primaryURL": "https://www.microsoft.com/en-us/corporate-responsibility/digital-skills/ai-skills-for-educators"
          },
-      {
-        "portalName": "MakeCode Arcade",
-        "primaryURL": "https://arcade.makecode.com/"
-                "secondaryURLs": [
-          {
-            "icon": "Start Page",
-            "url": "https://www.microsoft.com/en-au/makecode"
-          }
-        ]
-         },
-      {
+        {
         "portalName": "Microsoft Imagine Cup Junior In-a-Box",
         "primaryURL": "https://imaginecup.microsoft.com/junior"
          }