Merge topic 'ci-openwatcom'

14f2dbad03 ci: Add Open Watcom 1.9 nightly CI job
94404e912e Tests: Disable SubDirSpaces test on Open Watcom

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Ben Boeckel <ben.boeckel@kitware.com>
Merge-request: !6635