[v18.x backport] Add test-child-process-pipe-dataflow skip
requested to merge github/fork/JaneaSystems/test-child-process-pipe-dataflow-skip into v18.x-staging
Added skip to two tests (test-child-process-pipe-dataflow and test-child-process-stdio-reuse-readable-stdio) on Windows. We already had this on main, added it to v18 as well.