Remove unused SSR handler. (#6873)

### Description

Removing an unused dependency. It was throwing out logs that finally got
under my skin enough to fix.

Note: CI failure is unrelated. It only ran because the pnpm-lock.yaml changed for an unrelated dependency.

docs/package.json

@@ -19,7 +19,6 @@
     "@headlessui/react": "^1.7.17",
     "@heroicons/react": "1.0.6",
     "@mdx-js/react": "^3.0.0",
-    "@react-aria/ssr": "3.9.0",
     "@react-spring/web": "^9.7.3",
     "@sentry/nextjs": "^7.88.0",
     "@vercel/analytics": "^0.1.1",

docs/pages/_app.tsx

@@ -1,7 +1,6 @@
 import "../styles.css";
 import "../custom.css";
 
-import { SSRProvider } from "@react-aria/ssr";
 import type { AppProps } from "next/app";
 import type { ReactNode } from "react";
 import { Analytics } from "@vercel/analytics/react";
@@ -26,28 +25,26 @@ if (typeof window !== "undefined" && !("requestIdleCallback" in window)) {
 
 export default function Nextra({ Component, pageProps }: NextraAppProps) {
   return (
-    <SSRProvider>
-      <>
-        {/**
-         * Globally defined svg linear gradient, for use in icons
-         */}
-        <svg height="0px" width="0px">
-          <defs>
-            <linearGradient
-              id="pink-gradient"
-              x1="0%"
-              x2="100%"
-              y1="0%"
-              y2="100%"
-            >
-              <stop offset="0%" stopColor="rgba(156, 81, 161, 1)" />
-              <stop offset="70%" stopColor="rgba(255, 30, 86, 1)" />
-            </linearGradient>
-          </defs>
-        </svg>
-      </>
+    <>
+      {/**
+       * Globally defined svg linear gradient, for use in icons
+       */}
+      <svg height="0px" width="0px">
+        <defs>
+          <linearGradient
+            id="pink-gradient"
+            x1="0%"
+            x2="100%"
+            y1="0%"
+            y2="100%"
+          >
+            <stop offset="0%" stopColor="rgba(156, 81, 161, 1)" />
+            <stop offset="70%" stopColor="rgba(255, 30, 86, 1)" />
+          </linearGradient>
+        </defs>
+      </svg>
       <Component {...pageProps} />
       <Analytics />
-    </SSRProvider>
+    </>
   );
 }