ci: speedup local Windows builds (#8202)
ci: speedup local Windows builds (#8202)

Remove some code to troubleshoot full disk problems. These problems have
been resolved for a while, and the checks are very slow on my
workstation. If the problems ever come back, we can add these back. Note
that the somewhat faster checks in `ci/kokoro/windows/build.ps1` are
still there.
googleapis/google-cloud-cpp,googleapis/google-cloud-cpp,googleapis/google-cloud-cpp,googleapis/google-cloud-cpp