Correct cmake_minimum_required for CMake4
Fix paths for pkgconfig file installation
https://bugs.gentoo.org/951922
https://bugs.gentoo.org/863050
--- a/CMakeLists.txt	2025-03-24 15:32:02.295787034 +0300
+++ b/CMakeLists.txt	2025-03-24 15:33:46.099775849 +0300
@@ -1,6 +1,6 @@
+cmake_minimum_required(VERSION 3.5)
 PROJECT (FANN)
 #SET(CMAKE_VERBOSE_MAKEFILE ON)
-cmake_minimum_required(VERSION 2.8)
 
 SET(CMAKE_MODULE_PATH
 	${CMAKE_SOURCE_DIR}/cmake/Modules 
@@ -16,7 +16,6 @@
 
 configure_file( ${CMAKE_SOURCE_DIR}/cmake/fann.pc.cmake ${CMAKE_CURRENT_BINARY_DIR}/fann.pc @ONLY )
 
-SET(PKGCONFIG_INSTALL_DIR /lib/pkgconfig)
 
 ########### install files ###############