fix test to be ready for Windows

Author: svlandeg

tests/test_select_gen.py

@@ -1,3 +1,4 @@
+import os
 import subprocess
 import sys
 from pathlib import Path
@@ -10,8 +11,8 @@
 @needs_py39
 def test_select_gen() -> None:
     result = subprocess.run(
-        [sys.executable, "scripts/generate_select.py"],
-        env={"CHECK_JINJA": "1"},
+        [sys.executable, Path("scripts") / "generate_select.py"],
+        env={**os.environ, "CHECK_JINJA": "1"},
         check=True,
         cwd=root_path,
         capture_output=True,