bootstrap scripts should preload with low priority. This allows the browser to prefer loading paint blocking resources like images even if they arrive after the script preload has been processed

Author: gnoff

packages/react-dom-bindings/src/server/ReactFizzConfigDOM.js

@@ -5467,6 +5467,7 @@ function preloadBootstrapScript(
     rel: 'preload',
     href: src,
     as: 'script',
+    fetchPriority: 'low',
     nonce,
     integrity,
     crossOrigin,