Similar to commit 1f24d35033 (cppunittester:
use a dedicated desktop on Windows, 2023-07-09), this change allows to run
UI tests on Windows without them interferring with what you are doing.
The code testing LIBO_TEST_DEFAULT_DESKTOP environment variable to avoid
the separate desktop, and creating it, is extracted to a new function in
systools.
Change-Id: I6df3cb4ae581ae289e49b47d3135d01f632fbd95
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/170615
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
69586e8381