www/py-html5rdf: Fix build with Python 3.14+

PR: 295663
Reported by: Dean E. Weimer <dweimer@dweimer.net>
Obtained from: https://github.com/RDFLib/html5rdf/commit/3b49bab9e4ca79e54d37f47711f558b525eb2db3

		https://github.com/RDFLib/html5rdf/commit/eb0fbab7ba6b7b855c150c3fe42633d860f629c1