[ci] Update to latest version of cicleci windows orb

See https://github.com/emscripten-core/emscripten/pull/21110

.circleci/config.yml

diff --git a/.circleci/config.yml b/.circleci/config.yml
index 3b44851..da09195 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -1,7 +1,7 @@
 version: 2.1
 
 orbs:
-  win: circleci/windows@1.0.0
+  win: circleci/windows@5.0
 
 executors:
   bionic:
@@ -108,7 +108,7 @@
       - test-macos
   test-windows:
     executor:
-      name: win/vs2019
+      name: win/server-2019
       shell: bash.exe
     environment:
       # We need python installed before we can test anytyhing.