[scripts] ensure files use 'utf-8' encoding and '\n' newlines (#7872)

scripts/export_tests.py

@@ -71,7 +71,7 @@ def get_test_source(extr, *, cache={}):
         tests = cache[extr.__module__]
     except KeyError:
         path = sys.modules[extr.__module__].__file__
-        with open(path) as fp:
+        with util.open(path) as fp:
             lines = fp.readlines()
         tests = cache[extr.__module__] = extract_tests_from_source(lines)
     return tests.get(extr.url) or ("",)