Update CMakePresets.json for Windows build issue with Cmake 4.x

[Hitesh-ed]

Issue:
CMake 4.x fails to configure the SentencePiece dependency because its CMakeLists.txt declares cmake_minimum_required(VERSION 3.1), which is no longer compatible (it has to be atleaset 3.5 when using latest Cmake 4.x for build).

Solution:
Adding the following cache variable in CMakePresets.json to enforce modern policies automatically:

"cacheVariables": {
  "CMAKE_POLICY_VERSION_MINIMUM": "3.5"
}

# Pretends old CMake minimums below 3.5 are OK (fixes SentencePiece 3.1 issue automatically)

This ensures all developers can run "cmake --preset windows" without hitting legacy compatibility or deprecation issues.

[jan-wassenberg]

Nice, thanks for adding. We are only able to accept changes to the dev branch, would you please retarget the PR?