fix: enable CMP0177 for CMake >= 3.31

Add a version-guarded cmake_policy(SET CMP0177 NEW) to src/Index.cmake for CMake 3.31 and newer to normalize install directories. The policy is applied alongside existing policy settings to ensure consistent install directory behavior on newer CMake versions.

Co-Authored-By: Claus Klein <1833050+ClausKlein@users.noreply.github.com>

Author: aminya

src/Index.cmake

@@ -18,6 +18,11 @@ if(POLICY CMP0141)
   cmake_policy(SET CMP0141 NEW)
 endif()
 
+if(CMAKE_VERSION VERSION_GREATER_EQUAL "3.31.0")
+  # normalize install directories
+  cmake_policy(SET CMP0177 NEW)
+endif()
+
 # only useable here
 set(ProjectOptions_SRC_DIR "${CMAKE_CURRENT_LIST_DIR}")