Fix build failure with CMake >= 4.0

[mityu]

CMake 4.0 dropped backward compatibility for CMake < 3.5, therefore this library can't build with CMake 4.0 or later.
(cf: https://cmake.org/cmake/help/latest/release/4.0.html#deprecated-and-removed-features)

This PR updates CMakeLists.txt and some submodule libraries (glfw and glslang) to fix it.

Reproduce steps

Environment

• macOS Sequoia 15.4.1
• CMake 4.0.2 (installed with Homebrew)

Executed commands

git clone https://github.com/benikabocha/saba
cd saba
mkdir build
cd build
cmake ..

Output:

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.


-- Configuring incomplete, errors occurred!

[mityu]

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