Cancel pipelines on new push in samples repo

[wmmc88]

see microsoft/windows-drivers-rs#363

[wmmc88]

@svasista-ms this pr hasn't been merged in yet. it should remain open until its merged

[svasista-ms]

Closed it by mistake, I mistook this to be a different issue. The PR #42 can't be merged until a new version wdk-build (which has the fix for the build pipeline failure). I'll revisit this once the new version is available.