SystemTools: Revert "use CopyFile on Windows"

Revert !327 (merged). CopyFile also copies attributes, modification times, and other things that do not match our previous semantics.

assigned to @brad.king

mentioned in merge request !327 (merged)

Do: merge

mentioned in commit b238feaa

merged manually

mentioned in merge request cmake/cmake!10323 (closed)

mentioned in issue cmake/cmake#26378