Merge topic 'ctest-build-and-test'

2a5ecbdf1a ctest: Restore cleanup of load_command plugins
8e4fdafd0a cmCTestBuildAndTest: Improve RunCMake method return type

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: buildbot <buildbot@kitware.com>
Merge-request: !9916