fix(telemetry): trim the Read This First panel to ten rows

The debug-log notice on Log-Derived Insights was two grid rows taller than its
content needs, pushing the first data row further down than necessary. Rendered
the panel to confirm the markdown still fits with no clipping.

It is the first panel in the dashboard, so no other panel's stored y needed to
change - Grafana's vertical compaction closes the gap.

docker/telemetry/grafana/dashboards/log-derived-insights.json

@@ -220,7 +220,7 @@
       "type": "text",
       "title": "Read This First — Debug Log Requirement",
       "gridPos": {
-        "h": 12,
+        "h": 10,
         "w": 24,
         "x": 0,
         "y": 0