Fix newline

Author: johnslavik

Lib/test/test_repl.py

@@ -74,7 +74,7 @@ def new_startup_env(*, code: str, histfile: str = ".pythonhist"):
     with os_helper.temp_dir() as tmpdir:
         filename = os.path.join(tmpdir, "pythonstartup.py")
         with open(filename, "w") as f:
-            f.write(os.linesep.join(code.splitlines()))
+            f.write('\n'.join(code.splitlines()))
         yield {"PYTHONSTARTUP": filename, "PYTHON_HISTORY": os.path.join(tmpdir, histfile)}