`PluggyTeardownRaisedWarning` in pytest workflow

[blakeNaccarato]

Transitive dependency pluggy must be on 1.4.0 now, and is now warning PluggyTeardownRaisedWarning (see log, a link which will eventually break/expire). Because test warnings are promoted to exceptions, this fails CI. In order to stop the bleeding, let's fix it as follows:

• [x] Pin pluggy to prior release, 1.3.0 in main to get the workflow working again for now
• [ ] Unpin pluggy in a PR and follow the source of the warning. Is the warning a legitimate concern for the test suite?
• [ ] Can the right thing be done here, or does an upstream dependency need changing?
• [ ] If time permits, upstream the fix to the offending dependency
• [ ] When the issue is resolved, merge the PR or unpin pluggy in main

[blakeNaccarato]

This doesn't seem to be raised in the logs anymore, after 56de64c30fa4e78f7840975fbe64dd1899c8112a and closing #167.