Windows tests not running in CI

[otbrown]

See for example: https://github.com/QuEST-Kit/QuEST/actions/runs/26815691262/job/79056757127

Which has the following outpur:

Run ctest -j2 --output-on-failure --schedule-random -E "density evolution"
  ctest -j2 --output-on-failure --schedule-random -E "density evolution"
  shell: C:\Program Files\PowerShell\7\pwsh.EXE -command ". '{0}'"
  env:
    build_dir: build
    depr_dir: build/tests/deprecated
Test project D:/a/QuEST/QuEST/build
No configuration for testing specified, use '-C <cfg>'.
No tests were found!!!

[otbrown]

Looks like breaking change was in #758:

• Last working Windows test run in devel: https://github.com/QuEST-Kit/QuEST/actions/runs/26488925440/job/78002320612
• First skipped Windows test run in devel: https://github.com/QuEST-Kit/QuEST/actions/runs/26552354466/job/78216932430

[otbrown]

Could be as simple as adding -C Release to the ctest line: https://stackoverflow.com/questions/78500315/ctest-test-not-available-without-configuration 🤞

Just a consequence of VS relying on configurations, and test discovery now being deferred.