(PUP-2349) Add windows specific expectation for deprecation_warning

Previously, the spec test assumed that no deprecation warnings would be issued.
However, the test relies on puppet using the source_permissions of the
source, and that behavior is deprecated on Windows. As a result, the test
was failing on Windows.

This commit updates the test to expect only the "Copying owner/mode/group/.."
deprecation warning on Windows, and no deprecation warnings on other platforms.