Backport of "gst-env: Windows: Fix looking for cmd_or_ps.ps1 in the wrong directory" into 1.18
Backport of !238 (merged) "gst-env: Windows: Fix looking for cmd_or_ps.ps1 in the wrong directory".
Commits:
- d5b6cc88 gst-env: Windows: Fix looking for cmd_or_ps.ps1 in the wrong directory