Add beta request nav toggle

backend/app/runtime.py

@@ -39,6 +39,7 @@ _BOOL_FIELDS = {
     "site_login_show_local_login",
     "site_login_show_forgot_password",
     "site_login_show_signup_link",
+    "site_nav_show_requests",
 }
 _SKIP_OVERRIDE_FIELDS = {"site_build_number", "site_changelog"}