Unit test completion could be faster

[mikeingold]

The CI action for running tests currently takes on the order of 20 minutes to complete in GitHub. I suspect that this will be improved via (#67), but additional work could probably be done, e.g.:

• Minimize the precision of all @test integration rules to balance test passing with compute time

[JoshuaLampert]

Sounds good. We could also split up the tests into multiple CI GitHub Action runs, where each GitHub Action job runs a different subset of the tests.

[mikeingold]

This was helped somewhat by #96, which improved overall performance by strong 10%.

[mikeingold]

This was helped again by #100, which reduced CI time by about 2 minutes.