Add a variant Cockpit logs entry needle

When systemd is at the top of the list there's a bit of a grey
highlight that throws off the match.

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

needles/cockpit/logs_entry-systemd-top-20250911.json

@@ -0,0 +1,15 @@
+{
+  "area": [
+    {
+      "type": "match",
+      "xpos": 907,
+      "height": 15,
+      "width": 53,
+      "ypos": 545
+    }
+  ],
+  "properties": [],
+  "tags": [
+    "cockpit_logs_entry"
+  ]
+}