ci: don't SSR private env var

Author: ascorbic

demos/default/pages/env.tsx

@@ -6,14 +6,24 @@ function EnvTest() {
     <div>
       <h1>Environment Variables</h1>
       <a href="https://nextjs.org/docs/basic-features/environment-variables">Read Docs</a>
-      <p>By default environment variables are only available in the Node.js environment, meaning they won&apos;t be exposed to the browser.</p>
       <p>
-        <code>NEXT_PUBLIC_</code> environment variables are available in the browser, and can be used to configure the application.
+        By default environment variables are only available in the Node.js environment, meaning they won&apos;t be
+        exposed to the browser.
+      </p>
+      <p>
+        <code>NEXT_PUBLIC_</code> environment variables are available in the browser, and can be used to configure the
+        application.
+      </p>
+      <p>
+        ✅ Public Environment token found:{' '}
+        <code>{process.env.NEXT_PUBLIC_GREETINGS || 'NOT FOUND (something went wrong)'}</code>
+      </p>
+      <p>
+        ❌ Private Environment token should not be found:{' '}
+        <code>{(typeof document !== 'undefined' && process.env.TEST_ENV_VAR) || 'Everything worked'}</code>
       </p>
-      <p>✅ Public Environment token found: <code>{process.env.NEXT_PUBLIC_GREETINGS || 'NOT FOUND (something went wrong)'}</code></p>
-      <p>❌ Private Environment token should not be found:   <code>{process.env.TEST_ENV_VAR || 'Everything worked'}</code></p>
     </div>
   )
 }
 
-export default EnvTest
+export default EnvTest