rueml_yaml package - deprecated

[lwasser]

Our current workflow to update contribs is broken due to deprecated functionality in the rueml-yaml package.

the error is

https://github.com/pyOpenSci/pyopensci.github.io/actions/runs/7054535271/job/19203553994#step:5:91

"safe_load()" has been removed, use

  yaml = YAML(typ='safe', pure=True)
  yaml.load(...)

instead of file "/opt/hostedtoolcache/Python/3.10.13/x64/lib/python3.10/site-packages/pyosmeta/file_io.py", line 76

            return ruamel.yaml.safe_load(f)

this seems like a quick fix but it could be worth considering switching to the yaml standard lib that comes with Python rather than calling a dependency.