[Repo Assist] feat: add TaskSeq.sum, sumBy, sumByAsync, average, averageBy, averageByAsync#304

dsyme merged 3 commits intomainfsprojects/FSharp.Control.TaskSeq:mainfrom

repo-assist/feat-sumby-averageby-2026-03-8d8d6841f6117a18fsprojects/FSharp.Control.TaskSeq:repo-assist/feat-sumby-averageby-2026-03-8d8d6841f6117a18Copy head branch name to clipboard