windows install script does not check clang version

[chtenb]

I ran into this issue when I installed a new version of koka, and apparently the minimum required clang version had been bumped.

C:\Program Files\Microsoft Visual Studio\2022\Professional\VC\Tools\MSVC\14.40.33807\include\yvals_core.h(898,1): error:
      static assertion failed: error STL1000: Unexpected compiler version, expected Clang 17.0.0 or newer.
_EMIT_STL_ERROR(STL1000, "Unexpected compiler version, expected Clang 17.0.0 or newer.");
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
C:\Program Files\Microsoft Visual Studio\2022\Professional\VC\Tools\MSVC\14.40.33807\include\yvals_core.h(519,44): note:
      expanded from macro '_EMIT_STL_ERROR'
#define _EMIT_STL_ERROR(NUMBER, MESSAGE)   static_assert(false, "error " #NUMBER ": " MESSAGE)
                                           ^             ~~~~~
1 error generated.
util(1, 1): build error: user error (error  : command failed (exit code 1)
command: "c:/Program Files/LLVM/bin/clang-cl.exe" -DWIN32 -nologo -Wno-everything -Wall -Wextra -Wpointer-arith -Wshadow -Wstrict-aliasing -Wno-unknown-pragmas -Wno-missing-field-initializers -Wno-unused-parameter -Wno-unused-variable -Wno-unused-value -Wno-cast-qual -Wno-undef -Wno-reserved-id-macro -Wno-unused-macros -Wno-cast-align -Wno-extra-semi-stmt -Wno-extra-semi -Wno-float-equal -MDd -Zi -FS -O1 -D__clang_msvc__ -EHs -TP -c -I c:/Users/chiel.tenbrinke/AppData/Local/koka/share/koka/v3.1.2/kklib/include -DKK_MIMALLOC=8 -Fo.koka/v3.1.2/clang-cl-debug-44724a/util.obj .koka/v3.1.2/clang-cl-debug-44724a/util.c)

Failed to compile util.kk

> clang --version
clang version 16.0.6
Target: x86_64-pc-windows-msvc

The install script for windows does not seem to check the installed version of clang, just whether it exists on the system.