next.js

11b01e06 - Update parallelizing tasks with webpackBuildWorker config (#56287)

Update parallelizing tasks with webpackBuildWorker config (#56287) This updates to make build/server tracing parallelized with our webpack compilations so that it can start right after the server compilation is finished instead of after all compilations are finished. This parallelizing requires the `experimental.webpackBuildWorker` config be enabled and doesn't change behavior without it. Part of this also cleans up our plugin state restoring/handling to use serializable structures instead of serializing/deserializing manually.