MSVC: Fix MSVC_TOOLSET_VERSION for VS 2019 v142 toolset

This was forgotten in commit 626c51f47b (VS: Update for Visual Studio
2019 Preview 2, 2019-01-24, v3.14.0-rc1~74^2) when the toolset was
first renumbered to `v142`.

Issue: #19125

Modules/Platform/Windows-MSVC.cmake

@@ -71,7 +71,10 @@ if(NOT MSVC_VERSION)
     message(FATAL_ERROR "MSVC compiler version not detected properly: ${_compiler_version}")
   endif()
 
-  if(MSVC_VERSION GREATER_EQUAL 1910)
+  if(MSVC_VERSION GREATER_EQUAL 1920)
+    # VS 2019 or greater
+    set(MSVC_TOOLSET_VERSION 142)
+  elseif(MSVC_VERSION GREATER_EQUAL 1910)
     # VS 2017 or greater
     set(MSVC_TOOLSET_VERSION 141)
   elseif(MSVC_VERSION EQUAL 1900)