This avoids relying on finding these dependencies in $PATH while
running the tests. Some tests may set PATH="" while executing them,
which previously caused those tests to fail in this build setup.
The same is not an issue with MSVC builds with
-DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreadedDLL, because those
DLLs are also available in global system directories (including
DLLs such as msvcp140.dll and vcruntime140.dll).
Ninja isn't documented as one of the tools provided by the CI runner
images, but it used to be available implicitly installed before
in the windows-2022 images. Since the 20230918.1.0 image update,
it no longer is available out of the box; see
https://github.com/actions/runner-images/issues/8343.
Martin Storsjö