Use CTest dynamic resource spec generation

[KyleFromNVIDIA]

Description

CMake has supported dynamic resource spec generation since 3.28. Since we now require 3.30, use this feature instead of implementing it ourselves.

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.
• The cmake-format.json is up to date with these changes.
• I have added new files under rapids-cmake/
  • I have added include guards (include_guard(GLOBAL))
  • I have added the associated docs/ rst file and update the api.rst

[bdice]

This looks fine to me, overall.

[KyleFromNVIDIA]

@robertmaynard gave me his approval offline. Merging.

[KyleFromNVIDIA]

/merge