Update distro-metadata.json (#689)

Remove broken link

Author: sharpenedblade

docs/tools/distro-metadata.json

@@ -72,14 +72,6 @@
         "https://github.com/t2linux/T2-Ubuntu/releases/download/v6.18.5-1/ubuntu-unity-24.04-6.18.5-t2-noble.iso.02"
       ]
     },
-    {
-      "name": "Ubuntu Unity 25.10 - Questing Quokka",
-      "iso": [
-        "https://github.com/t2linux/T2-Ubuntu/releases/download/v6.16.6-1/ubuntu-unity-25.10-6.16.6-t2-questing.iso.00",
-        "https://github.com/t2linux/T2-Ubuntu/releases/download/v6.16.6-1/ubuntu-unity-25.10-6.16.6-t2-questing.iso.01",
-        "https://github.com/t2linux/T2-Ubuntu/releases/download/v6.16.6-1/ubuntu-unity-25.10-6.16.6-t2-questing.iso.02"
-      ]
-    },
     {
       "name": "Linux Mint - Cinnamon",
       "iso": [
@@ -115,4 +107,4 @@
       ]
     }
   ]
-}
+}