Numerous vulnerabilities in package from PyPI

[bittner]

The organization I work with uses Nexus as a proxy for downloading installable artifacts and Sonartype Repository Firewall to scan those artifacts. It blocks html5validator v0.4.2 (e.g. when installed using Pip) as the security scan detects numerous vulnerabilities.

Vulnerability	Severity
CVE-2016-1000031	9.8
CVE-2019-17571	9.8
CVE-2022-23305	9.8
CVE-2016-3092	7.5
CVE-2021-28165	7.5
CVE-2021-4104	7.5
CVE-2022-2048	7.5
CVE-2022-23302	8.8
CVE-2022-23307	8.8
CVE-2023-24998	7.5
CVE-2023-26464	7.5
CVE-2023-36478	7.5

All of those issues seem to be related to Java, most of them are in the orbit of Log4j. That said, it's likely that this project can't do anything about it, but I thought I let people know that some users are affected.

[bittner]

Related: #123, validator/validator#1287