* build: use 32-core Windows ARC runners for build jobs
* ci: add siso patch to retry ERROR_INVALID_PARAMETER on ninja file open
The existing patch removes the redundant per-chunk re-open in
fileParser.readFile, but the single remaining os.Open per subninja can
still hit the bindflt race under the ~90k-file concurrent open burst on
the 32-core Windows runners. Layer a second patch on top that wraps that
open in a Windows-only 5-attempt retry (5-80ms backoff) so a single
transient failure no longer aborts the whole manifest load.