Update to newest version of lxml

[TakumiHendricksDev]

I'm running into dependency issues where I am required to downgrade lxml to 4.9.4 from 5.1.0. Would be really nice to have this upgraded as I have other packages depending on this package as well.

[TakumiHendricksDev]

Here is the branch for this issue.

[patrys]

This is also blocking for users of Python 3.13 since lxml versions before 5.x are incompatible.

[landonshumway-ia]

@gnongsie This ticket has been open for over 6 months with no response, which is blocking Python 3.13 migrations for clients in production. As of now, the latest version of lxml is 6.0.2, and updating this dependency would resolve these compatibility issues.

We understand maintaining SDKs requires development resources, but given how critical Authorize.net is for production payment processing, we hope Authorize.net can prioritize dependency updates for their SDKs. Could you or someone on your team please provide a timeline for addressing this, or would you be willing to review the PR linked above? Thank you.