[Repo Assist] test: add SideEffects and ImmTaskSeq variant tests for chunkBy/chunkByAsync#396

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

repo-assist/test-chunkby-sideeffects-20260420-7b06bb767b100bf2fsprojects/FSharp.Control.TaskSeq:repo-assist/test-chunkby-sideeffects-20260420-7b06bb767b100bf2Copy head branch name to clipboard