avoid AttributeError in tests

StringIO in tests do not have all attributes, ignore it

src/extract_otp_secrets.py

@@ -133,7 +133,11 @@ def main(sys_args: list[str]) -> None:
     # allow to use sys.stdout with with (avoid closing)
     sys.stdout.close = lambda: None  # type: ignore
     # set encoding to utf-8, needed for Windows
-    sys.stdout.reconfigure(encoding='utf-8')  # type: ignore
+    try:
+        sys.stdout.reconfigure(encoding='utf-8')  # type: ignore
+    except AttributeError:  # '_io.StringIO' object has no attribute 'reconfigure'
+        # StringIO in tests do not have all attributes, ignore it
+        pass
 
     args = parse_args(sys_args)