[cmake] Require minimum CMake version 3.5

Soon CMake 4.0 will be released. It requires that projects
set a minimum required CMake version of 3.5. There is a
workaround with an additional flag, but it would is better
to increase the minimum required version.

CMakeLists.txt

@@ -1,6 +1,6 @@
-# 3.5 is actually available almost everywhere, but this a good minimum.
-# 3.14 as the upper policy limit avoids CMake deprecation warnings.
-cmake_minimum_required(VERSION 3.4...3.14)
+# 3.5 is actually available almost everywhere.
+# 3.30 as the upper policy limit avoids CMake deprecation warnings.
+cmake_minimum_required(VERSION 3.5...3.30)
 
 # enable MSVC_RUNTIME_LIBRARY target property
 # see https://cmake.org/cmake/help/latest/policy/CMP0091.html

test/CMakeLists.txt

@@ -3,7 +3,6 @@ find_package(Threads REQUIRED)
 set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
 set(BUILD_MOCK ON CACHE BOOL "" FORCE)
 set(INSTALL_GTEST OFF CACHE BOOL "" FORCE)
-set(CMAKE_POLICY_DEFAULT_CMP0048 NEW)
 
 if(YAML_USE_SYSTEM_GTEST)
   find_package(GTest)