MAHOUT-454 Notebook Testing

[rawkintrevo]

Purpose of PR:

Please give a short description of what this PR is for.

Important ToDos

Please mark each with an "x"

• [x] A JIRA ticket exists (if not, please create this first)[https://issues.apache.org/jira/browse/mahout/]

• [x] Title of PR is "MAHOUT-XXXX Brief Description of Changes" where XXXX is the JIRA number.

• [x] Created unit tests where appropriate

• [ ] Added licenses correct on newly added files

• [x] Assigned JIRA to self

• [x] Successfully built and ran all unit tests, verified that all tests pass locally.

If all of these things aren't complete, but you still feel it is appropriate to open a PR, please add [WIP] after MAHOUT-XXXX before the descriptions- e.g. "MAHOUT-XXXX [WIP] Description of Change"

Does this change break earlier versions?

Is this the beginning of a larger project for which a feature branch should be made?

Evidence of successful run: https://github.com/apache/mahout/actions/runs/10724164981

[rawkintrevo]

in it's current implementation- the test fails if any cell in any notebook fails- it is possible w/o much extra effort to layer in a testing framework (ie pytest) but i didn't realize we had that already in, or understand enough about it, i would make "add pytest to notebook tests' a follow on issue

[rawkintrevo]

or, discussion point- add tests in pytest for the notebooks