fix: Uproot tests now work with Awkward 2.0.0.

[jpivarski]

It works offline with dask-awkward from its main branch, but the tests will still fail until a dask-awkward release is made containing dask-contrib/dask-awkward#119. We just need a dask-awkward 2022.12a3, @douglasdavis.

I'm impressed that the parse_version("1") < parse_version(awkward.__version__) < parse_version("2") line survived this long in Uproot v5. I simply misunderstood what "< parse_version("2") meant: I must have thought that it excluded all the 2.0.0rcX pre-releases, but that's not how version ordering works. Okay. The version range has been fixed, and it no longer has an upper cap. (We have no reason to believe that there will be an Awkward 3.x, or that it might be disruptive.)

The other "fix", twiddling how the tests get data out of an Awkward Array, side-steps the bug that is fixed in scikit-hep/awkward#1993 (and now there's an Awkward test for it, so we don't rely on Uproot's test).

Uproot 5.0.0 can't be released until this is merged and this can't be merged until dask-awkward 2022.12a3 exists. But we don't need scikit-hep/awkward#1993; this PR is independent of that reaching a release. That's the order of dependencies.

[jpivarski]

I'm going to break a rule about never merging one's own PR without a review. In this case, the differences are uncontroversial and this is blocking the 5.0.0 release—I don't want Awkward 2 to be released without Uproot 5 for a significant length of time, since the mismatch can cause problems.

This will be used as an example to clarify when we can do that. (There are other rules with exceptions, like committing directly to main is in fact a good thing to do when you're changing version numbers or toggling tests.)