Package depends on PyXB which is at end-of-life

[mmuckley]

One of the dependencies includes pyxb, which as noted by the maintainer is at end-of-life, and other solutions are recommended.

Perhaps the most pressing item is that pyxb has a deprecated idiom for importing from collections: PR 111. This is a warning that has been showing up in my tests.

I just tested ISMRMRD in Python 3.9 and I think it's still working despite the deprecation, but long-term stability of the Python ISMRMRD package could still be threatened by this dependency.

The best solution would probably be to remove the need for pyxb from ismrmrd. If this isn't possible, then perhaps ismrmrd could create its own fork of pyxb and merge PR 111.

[dchansen]

This was fixed a while back. Sorry for not replying sooner