Merge topic 'update-kwsys'

77ea15b797 Tests: Add case covering `cmake -E env` with empty environment variable
209dfc51d3 Merge branch 'upstream-KWSys' into update-kwsys
92a7104600 KWSys 2025-10-08 (3bae03fe)

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !11288