Automatically propagate minimum required CMake version

The package config takes the minimum required CMake version from the
main project.

Also introduce the maximum supported CMake version for policy management.

CMakeLists.txt

@@ -19,10 +19,17 @@ License along with this program.  If not, see
 
 cmake_minimum_required(VERSION 3.25)
 
-# If CMake >=3.24 is used, set policies up to v3.24 to NEW
-# if (NOT ${CMAKE_VERSION} VERSION_LESS 3.24)
-#     cmake_policy(VERSION 3.24)
-# endif()
+set(CMAKE_MAXIMUM_SUPPORTED_VERSION 3.28)
+
+# If CMAKE_VERSION <= CMAKE_MAXIMUM_SUPPORTED_VERSION is used, set policies up
+# to CMAKE_VERSION to NEW
+if (${CMAKE_VERSION} VERSION_LESS_EQUAL ${CMAKE_MAXIMUM_SUPPORTED_VERSION})
+    cmake_policy(VERSION ${CMAKE_VERSION})
+# If CMAKE_VERSION > CMAKE_MAXIMUM_SUPPORTED_VERSION is used, set policies up to
+# CMAKE_MAXIMUM_SUPPORTED_VERSION to NEW
+else ()
+    cmake_policy(VERSION ${CMAKE_MAXIMUM_SUPPORTED_VERSION})
+endif()
 
 project(NetlibF2C VERSION 1.4.2 LANGUAGES C)
 

packaging/NetlibF2CConfig.cmake.in

@@ -17,12 +17,19 @@ License along with this program.  If not, see
 <https://www.gnu.org/licenses/>.
 ]]
 
-cmake_minimum_required(VERSION 3.25)
-
-# If CMake >=3.24 is used, set policies up to v3.24 to NEW
-# if (NOT ${CMAKE_VERSION} VERSION_LESS 3.24)
-#     cmake_policy(VERSION 3.24)
-# endif()
+cmake_minimum_required(VERSION @CMAKE_MINIMUM_REQUIRED_VERSION@)
+
+set(CMAKE_MAXIMUM_SUPPORTED_VERSION @CMAKE_MAXIMUM_SUPPORTED_VERSION@)
+
+# If CMAKE_VERSION <= CMAKE_MAXIMUM_SUPPORTED_VERSION is used, set policies up
+# to CMAKE_VERSION to NEW
+if (${CMAKE_VERSION} VERSION_LESS_EQUAL ${CMAKE_MAXIMUM_SUPPORTED_VERSION})
+    cmake_policy(VERSION ${CMAKE_VERSION})
+# If CMAKE_VERSION > CMAKE_MAXIMUM_SUPPORTED_VERSION is used, set policies up to
+# CMAKE_MAXIMUM_SUPPORTED_VERSION to NEW
+else ()
+    cmake_policy(VERSION ${CMAKE_MAXIMUM_SUPPORTED_VERSION})
+endif()
 
 set(
     LoadStaticSharedTargets_DIR