curl: Restore build within CMake after update to 8.0.1

Restore changes from commit 2be5a7de4e (Build: Use imported target
`ZLIB::ZLIB` instead of variables, 2022-08-21, v3.25.0-rc1~97^2~10)
that were undone by the update to curl 8.0.1.  The code was moved.
1 file changed