Add a gnome-panel needle variant for aarch64(?)

This screen looks very slightly different on aarch64, it seems
like, not sure why.

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

needles/gnome/apps/gnome-panel/panel_screen_locked-20250409.json

@@ -0,0 +1,15 @@
+{
+  "area": [
+    {
+      "type": "match",
+      "xpos": 467,
+      "ypos": 286,
+      "height": 104,
+      "width": 90
+    }
+  ],
+  "properties": [],
+  "tags": [
+    "panel_screen_locked"
+  ]
+}