Explicitly set Same-Site:None on preview secret cookies (codesandbox#3713)

Fixes codesandbox#3617

Author: CompuIves

packages/sandbox-hooks/preview-secret.js

@@ -22,7 +22,7 @@ export const setPreviewSecret = secret => {
     cookieValue !== secret
   ) {
     if (secret) {
-      document.cookie = `${PREVIEW_SECRET_COOKIE_NAME}=${secret}`;
+      document.cookie = `${PREVIEW_SECRET_COOKIE_NAME}=${secret};samesite=none;secure;`;
       location.reload();
     } else {
       document.cookie = `${PREVIEW_SECRET_COOKIE_NAME}=; expires=Thu, 01 Jan 1970 00:00:01 GMT;`;