installation DEPRECATION warning with pip 25.1.1

[richardbrockie]

When building my app on Heroku, installing svglib with pip 25.1.1 gives the following warning:

DEPRECATION: Building 'svglib' using the legacy setup.py bdist_wheel mechanism, which will be removed in a future version. pip 25.3 will enforce this behaviour change. A possible replacement is to use the standardized build interface by setting the --use-pep517 option, (possibly combined with --no-build-isolation), or adding a pyproject.toml file to the source tree of 'svglib'. Discussion can be found at pypa/pip#6334

It looks like this might already be covered by pull request #378?

[github-actions]

Thank you for raising your first issue! Your help to improve svglib is much appreciated!