Awkward

Just like 1.8.0rc7, but this is not a release candidate. See the release candidates for all the changes with respect to 1.7.0.

The first non-release candidate to drop Python 2.7 and 3.5, and the first to support Python 3.10.

henryiii dropped `wheel` from pyproject.toml: PR 1322. Bumped pybind11 to 2.9.1: PR 1316. Avoided PyPI cuda wheel upload: PR 1313. Removed unnecessary static libraries from wheels: PR 1314.

agoose77 added `optiontype_outside_record` option to `ak.zip`: PR 1308. Fixed typo in ArrayBuilder documentation: PR 1326.

agoose77 and ianna found and fixed an indexing error in LayoutBuilder: PR 1303.

jpivarski fixed lost `behavior` in `ak.unzip` (prompted by Coffea tests of 1.8.0rc5): PR 1301.

Bump version number to try to upload to PyPI again. ([1.8.0rc4 might have failed](https://github.com/scikit-hep/awkward-1.0/actions/runs/1877841929) because of a resurgence of https://github.com/pypa/twine/issues/696).

henryiii updated the Python style to take advantage of Python 3.6 and above (format strings!): PR 1244, 1246. Fixed a problem associated with building twice: PR 1254. Added shellcheck: PR 1243. Updated pytest config: PR 1255. Added dependabot: PR 1263. Updated black: PR 1267. Added nox and pylint support: PR 1262. Updated style using pylint: PR 1275.

agoose77 and ianna fixed a segfault in reducers on >= 4-dimensional arrays with `axis != -1` (v1 and v2): PR 1274.

jpivarski allowed `ak.nan_to_num` arguments to be arrays: PR 1298. This is a blocker for https://github.com/scikit-hep/vector/pull/172, motivating the final push toward 1.8.0 release.

Reverted the PowerPC build: PR 1239.