Add compatibility for CMake 4.

--- cmake/CMakeLists.txt.orig	2026-08-25 20:05:26 UTC
+++ cmake/CMakeLists.txt
@@ -5,7 +5,7 @@
 # Everything should go into a win64.cmake equivalent.
 # -----------------------------------------------------------------------------
 
-cmake_minimum_required (VERSION 3.3.2) # Might compile lower, but untested
+cmake_minimum_required (VERSION 3.5.2) # Might compile lower, but untested
 project (cannonball)
 
 # -----------------------------------------------------------------------------