[SYCL][PI][L0] Upgrade L0 loader to v1.8.8 on Windows too (#7552)

This commit upgrades the L0 loader version to v1.8.8 on Windows too, so
the version is now the same on both Windows and Linux. The current
version on Windows is very old, and it lacks important features (e.g.,
importing external memory from Win32 handles, compiling `ze_tracer`),
which blocks the Render Kit products. I haven't seen any explanation or
evidence why the L0 loader has to be kept so old on Windows. I haven't
encountered any issues after upgrading, including with public graphics
drivers.

Author: atafra

sycl/plugins/level_zero/CMakeLists.txt

@@ -21,11 +21,7 @@ if (NOT DEFINED LEVEL_ZERO_LIBRARY OR NOT DEFINED LEVEL_ZERO_INCLUDE_DIR)
   if (NOT DEFINED SYCL_EP_LEVEL_ZERO_LOADER_SKIP_AUTO_UPDATE)
     set(SYCL_EP_LEVEL_ZERO_LOADER_SKIP_AUTO_UPDATE ${SYCL_EXTERNAL_PROJECTS_SKIP_AUTO_UPDATE})
   endif()
-  if (WIN32)
-    set(LEVEL_ZERO_LOADER_SOURCE_VERSION v1.2.3)
-  else()
-    set(LEVEL_ZERO_LOADER_SOURCE_VERSION v1.8.8)
-  endif()
+  set(LEVEL_ZERO_LOADER_SOURCE_VERSION v1.8.8)
 
   #TODO: Replace ExternalProject with FetchContent for better maintainance and
   #      cmake files simplification