acceptance/dashboards: unset MSYS_NO_PATHCONV before fault.py on Windows

MSYS_NO_PATHCONV=1 (set in the parent test.toml) prevents MSYS2 from
converting POSIX paths to Windows paths, causing Python to receive a
broken path (/c/a/... instead of C:\a\...) when invoking fault.py.
Unset it before the fault.py call, matching the pattern used by other
dashboard scripts before their bin helper invocations.

Co-authored-by: Denis Bilenko

Author: denik

acceptance/bundle/resources/dashboards/publish-failure-retry/script

@@ -6,6 +6,10 @@ cleanup() {
 }
 trap cleanup EXIT
 
+# unset MSYS_NO_PATHCONV so MSYS2 converts the script path to a Windows path
+# when invoking the Python interpreter (required for fault.py to be found on Windows).
+unset MSYS_NO_PATHCONV
+
 # Inject a single publish failure so the first deploy creates the dashboard
 # draft but fails to publish it.
 fault.py "POST /api/2.0/lakeview/dashboards/*" 400 0 1