dashboard: Unbreak npm build

I broke the build in #19 so this fixes that.

Turns out Copilot had originally generated a correct import statement (without
brackets), but I didn't trust it because it looked inconsistent with the
others, so I modified it. All hail our new AI overlords.

Signed-off-by: Aurélien Bombo <[email protected]>

pages/index.js

@@ -1,7 +1,7 @@
 import { useEffect, useState } from "react";
 import { DataTable } from "primereact/datatable";
 import { Column } from "primereact/column";
-import { Head } from "next/head";
+import Head from "next/head";
 import { weatherTemplate, getWeatherIndex } from "../components/weatherTemplate";