* volume: skip directory fsync on Windows
* ci: run the windows jobs for the whole vacuum path
Both windows jobs start the same weed mini cluster, so both exercise the
volume server's vacuum path, but only one of them watched a single file
in it. Cover the compact, reconcile and load files in both.
* volume: report a failed makeupDiff instead of discarding it
The cleanup removes assigned to the same err the makeupDiff failure was
held in, so an aborted compaction returned nil once both removes
succeeded. The master then recorded the vacuum as committed and the
volume reloaded against the discarded generation.
* volume: correct the fsyncDir comments after the windows skip
Both comments described the old shape, where windows fell through to a
sync whose error was swallowed.
* volume: keep the makeupDiff failure ahead of its cleanup errors
A failed remove of .cpd/.cpx outranked the failure that abandoned the
compaction, so the caller saw the cleanup error instead of the cause.
Log it and return the original, matching the Rust do_commit_compact. A
leftover temp file is rolled back by reconcile on the next start.