[v14.x backport] fs: improve fsPromises writeFile performance
requested to merge github/fork/MoritzLoewenstein/fs-writefile-performance-backport into v14.x-staging
backport of #37610 'sister' pr of #39838
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
backport of #37610 'sister' pr of #39838