Leverage CMake 4.2 introduction of UNWIND_INCLUDE for `find_package`

[robertmaynard]

Description

This allows rapids-cmake starting in 4.2 to correctly generate CMake config modules that gracefully error out instead of silently returning and producing weird downstream errors. These weird errors are generally around missing targets.

Checklist

• [x] I am familiar with the Contributing Guidelines.
• [x] New or existing tests cover these changes.