Increase minimum CMake version to 3.10

CMake 3.31 warns:

    CMake Deprecation Warning at CMakeLists.txt:1 (cmake_minimum_required):
      Compatibility with CMake < 3.10 will be removed from a future version of
      CMake.

      Update the VERSION argument <min> value or use a ...<max> suffix to tell
      CMake that the project does not need compatibility with older versions.

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.7)
+cmake_minimum_required(VERSION 3.10)
 
 # Default to a release build.
 if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)