Fix problem running unit regression tests on Windows.
Path-separator escaping is no longer working correctly.
Think its related to python3 change, but sending in unix-style paths in this instance works on Windows.
@@ -2803,6 +2803,7 @@ SILO_MODE = TestEnv.SILO_MODE
# Run our test script using "Source"
#
import visit
-visit.Source(TestEnv.params["script"])
+from pathlib import Path
+visit.Source(Path(TestEnv.params["script"]).as_posix())
