schtasks.exe /Change on a non-existent task writes to stderr and exits 1.
Inside the disk-cleanup function (EAP=Stop, wrapped by the exit-code-sensitive
prepare-win cleanup invoker), that leaked $LASTEXITCODE=1 all the way to the
result marker — DISM runs via Start-Process and does not reset it — so the
step failed with "Disk cleanup failed (exit 1)" even though everything worked.
On a freshly-deployed WS2025 the UpdateOrchestrator "Schedule Scan" task does
not exist, so this fired every run.
Replace the schtasks loop with Get-ScheduledTask | Disable-ScheduledTask,
which no-ops silently on a missing task and sets no process exit code.
Follow-up to fb5de6f; applied to both toolchains.
Simone
f91039b946