Incompatibility with lxml wheels on Python 3.13 – request for official compatibility matrix

[icarocd]

Summary:
When using python-xmlsec (v1.3.15+) with lxml (>=5.4.0) in Python 3.13, the following runtime error occurs:
RuntimeError: lxml & xmlsec libxml2 library version mismatch

Cause:

• lxml wheels embed libxml2
• python-xmlsec (via wheels or source) links against system-installed libxml2
• Mismatch occurs if these differ

Repro Steps:
pip install xmlsec==1.3.15
pip install lxml==5.4.0
run anything using both => runtime crash

Could this repo:

1. Document an official compatibility matrix (e.g. tested lxml + xmlsec + Python versions)?
2. Mention the need to install lxml with --no-binary lxml if using the pip wheels for xmlsec?
3. Offer optional linkage to system libxml2 via env var or flag?

This would help many consumers of python3-saml, pysaml2, and other XML signature flows.