chore: update pin for grafana

Author: mcp-registry-bot

servers/grafana/server.yaml

@@ -12,7 +12,7 @@ about:
 source:
   project: https://github.com/grafana/mcp-grafana
   branch: main
-  commit: 5ff432c30928e5cf93d419f194be73058e3a83c3
+  commit: d781f3c889913cf3d5e186a6047a124e36ee054c
 run:
   command:
     - --transport=stdio