chore(sponsors): Add Arcjet to /sponsors

Author: balazsorban44

docs/pages/sponsors.mdx

@@ -91,6 +91,11 @@ It would not be possible without the generous support of our sponsors.
 
 <div className="flex flex-wrap flex-row gap-8 md:gap-16 pt-8">
   {[
+    [
+      "https://arcjet.com/?ref=auth.js",
+      "https://avatars.githubusercontent.com/u/24397786?s=200&v=4",
+      "Arcjet",
+    ],
     [
       "https://descope.com",
       "https://avatars.githubusercontent.com/u/97479186?s=200&v=4",