The second change technically affects non-Windows, but the
behavior should be exactly the same:
* Packages no longer have access to `.msbuild` and `.nmake`
automatically; they now get them via a dependency on `msvc`.
* Update two CMake-based packages that call `make test` to
instead call `ctest` (`netcdf-cxx4` and `pegtl`).
CMake-based packages should do this because on Windows
`make test` will not generally work, but `ctest` does.
* Fix `openssl` "make test" on Windows (WRT prior point: not
a CMake-based package).
4a7508c9df