Bring the user's attention to --allow-non-packages

Because I myself forgot that this was already implemented as an option.

Author: mgedmin

CHANGES.rst

@@ -6,6 +6,9 @@ Changelog
 
 - Drop support for Python 3.8 and 3.9.
 
+- Mention the ``--allow-non-packages`` option when showing the error message
+  that rejects non-packages.
+
 
 0.23.0 (2025-10-14)
 -------------------

src/check_python_versions/cli.py

@@ -127,6 +127,7 @@ def check_package(where: str = '.', *, print: PrintFn = print) -> bool:
 
     if not is_package(where):
         print("no setup.py or pyproject.toml -- not a Python package?")
+        print("you may want to try check-python-versions --allow-non-packages")
         return False
 
     return True