The CMake 4.2 requirement was added only because its FindZLIB module
recognizes zlib 1.3.2 static library names on Windows, zs.lib and zsd.lib.
That is a local dependency lookup issue, not a project-wide CMake
requirement.

Keeping the minimum at CMake 3.x mainly helps the default CI setup, which
may still use the CMake version provided by the base image. Modern CI
systems can install a newer CMake when needed, but this project should not
require that unless it actually depends on CMake 4.2 behavior.

FreeImageRe already has a zlib dependency handler and builds zlib itself,
so it knows the install directory and expected library names. The fix should
stay in that handler by linking the generated zlib byproducts directly,
instead of raising the CMake requirement for every consumer.

Suggestion:

cmake_minimum_required(VERSION 3.24...4.2)