Log Message:
py-graphviz: updated to 0.20.3

Version 0.20.3
--------------

Revert improvements to the internal ``tools.deprecate_positional_args()``
decorator that caused false positive
``PendingDeprecationWarning: The signature of ... will be reduced``
warnings that have been misinterpreted in the 0.20.2 release process.

Version 0.20.2
--------------

Drop Python 3.7 support (end of life 27 Jun 2023).

Tag Python 3.11 and 3.12 support.

Add caveat about ``labe`` escaping/quoting to ``.node()`` and ``.render()``
API docs.

Document that ``doctest_skip_exe()`` lines in doctest should be ignored.

Improve internal ``tools.deprecate_positional_args()`` decorator
and fix incorect test assertion.

Update GitHub actions.

Pin ``pytest`` test dependency to ``<8.1`` as a workaround
for ``import file mismatch error`` related to ``conftest.py`` files,
in ``pytest 8.1.1``, see https://github.com/pytest-dev/pytest/issues/12123.