Add Github Actions for Windows (#24504)

Setup Installer CI (#25184), (#25191)

Co-authored-by: Zack Galbreath <zack.galbreath@kitware.com>
Co-authored-by: lou.lawrence@kitware.com <lou.lawrence@kitware.com>
Co-authored-by: Betsy McPhail <betsy.mcphail@kitware.com>

share/spack/qa/configuration/windows_config.yaml

@@ -0,0 +1,8 @@
+config:
+  locks: false
+  install_tree:
+    root: $spack\opt\spack
+    projections:
+      all: '${ARCHITECTURE}\${COMPILERNAME}-${COMPILERVER}\${PACKAGE}-${VERSION}-${HASH}'
+  build_stage:
+    - ~/.spack/stage