Misc cleanups around Netty4HttpPipeliningHandler#104642

DaveCTurner merged 3 commits intoelastic:mainelastic/elasticsearch:mainfrom

DaveCTurner:2024/01/23/Netty4HttpPipeliningHandler-cleanupsDaveCTurner/elasticsearch:2024/01/23/Netty4HttpPipeliningHandler-cleanupsCopy head branch name to clipboard