Upon completion of the `cu13` build, the outer 12.9 container merges both `cu12` and `cu13` wheels into a single cuda-cccl wheel, and uploads that via the standard CCCL CI artifact upload mechanisms.

This is a special version built for BleachBit. It installs in a portable style. This script may be run in an empty directory like `c:\projects`. (at your option) any later version.