address review feedback. Don't install ms-gsl with vcpkg

Author: dbarker

ci/setup_windows_ci_environment.ps1

@@ -10,9 +10,6 @@ $VCPKG_DIR = (Get-Item -Path ".\").FullName
 ./bootstrap-vcpkg.bat
 ./vcpkg integrate install
 
-# Microsoft.GSL
-./vcpkg "--vcpkg-root=$VCPKG_DIR" install ms-gsl:x64-windows
-
 # Google Benchmark
 ./vcpkg "--vcpkg-root=$VCPKG_DIR" install benchmark:x64-windows