build failure with cmake 4

[0-wiz-0]

cmake 4 deprecated support for versions < 3.5.
This causes the build to break with:

CMake Error at CMakeLists.txt:1 (CMAKE_MINIMUM_REQUIRED):
  Compatibility with CMake < 3.5 has been removed from CMake.

  Update the VERSION argument <min> value.  Or, use the <min>...<max> syntax
  to tell CMake that the project requires at least <min> but has been updated
  to work with policies introduced by <max> or earlier.

  Or, add -DCMAKE_POLICY_VERSION_MINIMUM=3.5 to try configuring anyway.

The fix is to increase the minimal required version number in CMakeLists.txt:

--- CMakeLists.txt.orig 2025-08-14 08:21:38.449707889 +0000
+++ CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 2.8.12 FATAL_ERROR)
+cmake_minimum_required(VERSION 3.5)
 project(libebur128 C)

 option(BUILD_SHARED_LIBS

and test/CMakeLists.txt:

$NetBSD$

--- test/CMakeLists.txt.orig    2025-08-14 08:22:36.261329563 +0000
+++ test/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 2.8.12)
+cmake_minimum_required(VERSION 3.5)

 set(ENABLE_TESTS OFF CACHE BOOL "Build test binaries, needs libsndfile")
 set(ENABLE_FUZZER OFF CACHE BOOL "Build fuzzer binary")

[fkobi]

Related: #135