tools: bump vswhere helper to 2.0.0

* enable explicit detection of prerelease VS versions with
  `set VSWHERE_WITH_PRERELEASE=1`

PR-URL: https://github.com/nodejs/node/pull/14557


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Bartosz Sosnowski <bartosz@janeasystems.com>