Does this package/repo support sponsorships ($$$)

No, we do not.

My company makes use of this package for username/password auth and really appreciate the work that's gone into it. We'd love to help ensure that this package remains well-maintained and continues to get important updates. Does this package/repo support sponsorships ($$$), and if not are there any plans to?

Just donate if they have a link.

Taking this opportunity to revisit this issue and restate that my company would love to sponsor this project, even if just to ensure that it has continued support. This wouldn't come with any expectation of increased support, prioritization, etc. We just want a way to (financially) say thanks!