Drop workaround property from KDE leftbar needle

It always matches, even when we're *not* working around the KDE
title bar issue, so we'd better not mark it as a workaround.

Signed-off-by: Adam Williamson <awilliam@redhat.com>

needles/anaconda/identification/leftbar_generic-kde-titlebar-20241128.json

@@ -8,13 +8,8 @@
       "xpos": 20
     }
   ],
-  "properties": [
-    {
-      "name": "workaround",
-      "value": "works around anaconda title bar being visible in KDE, which it should not be"
-    }
-  ],
+  "properties": [],
   "tags": [
     "leftbar_generic"
   ]
-}
+}