Switch to pyproject.toml format

[MilesCranmer]

1. Moves much of the package information to a pyproject.toml (required by some package managers like rye and poetry).
2. Sets upper bounds on celmech.
3. Removes torchvision as a dependency (not needed).
4. Uses globbing to specify package data.
5. Generates the version dynamically using setuptools_scm (it is now set in the pyproject.toml rather than in the version.py file - that gets generated at build time).
6. Switches to the multi-author format so we can add contributors.

I still need to do some testing. Also @dtamayo this doesn't fix the bug you pointed out in the email; we still need to fix that somehow.

[MilesCranmer]

FYI @dtamayo I think test_analytical.py uses the old rebound syntax?

ERROR: test_same_trajectory (spock.test.test_analytical.TestClassifier.test_same_trajectory)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/mcranmer/PermaDocuments/spock/spock/test/test_analytical.py", line 94, in test_same_trajectory
    sa = rebound.SimulationArchive('temp.bin')
         ^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: module 'rebound' has no attribute 'SimulationArchive'. Did you mean: 'Simulationarchive'?

[dtamayo]

This is amazing, thank you @MilesCranmer! Works perfectly on my end. Couldn't test in on the PyPI test server ahead of time, so I'll test that after merge.