ci/windows: fix zink msvc build-rules
When I added the build-rules for zink to the windows build, I accidentally added it to .windows-test-rules instead of .windows-build-rules. This seems to trigger a build-error if we trigger just a test due to a zink-change, but not a build.
Hopefully this fixes the problems Mike has had with Zink CI recently.
Fixes: a426d7c2 ("ci/windows: enable msvc builds of zink")