revup explodes on PRs with team reviewer

[anguslees]

Describe the bug
revup trips over PRs that have non-User (ie: team) reviewers.

reviewRequests.requestedReviewer can be a user or team. See https://docs.github.com/en/graphql/reference/unions#requestedreviewer

Expected behavior
Support team reviewers, or at least safely ignore non-User reviewers.

This is sufficient to fix it for me:

            for revs in this_node["reviewRequests"]["nodes"]:
+               if revs["requestedReviewer"]:
                    reviewers.add(revs["requestedReviewer"]["login"])
                    reviewer_ids.add(revs["requestedReviewer"]["id"])

To Reproduce
revup upload to create PR. Add a team reviewer to the PR via github UI. Attempt to run revup upload again.

Logs
Terminal output from the command. If possible, rerun the command with revup -v to get more verbose logs.

It's a private repo, so I can't point you at the PR, nor include the full logs. But this PR has a regular reviewer and a team reviewer - and I think the interesting bits of the logs are:

% revup -v upload
[...]
      "reviewRequests": {
       "nodes": [
        {
         "requestedReviewer": {
          "login": "joe_user",
          "id": "M...Q=="
         }
        },
        {
         "requestedReviewer": null
        }
       ]
      },
[...]
Traceback (most recent call last):
  File "/Users/gus/bin/revup", line 8, in <module>
    sys.exit(_main())
  File "/Users/gus/revup/lib/python3.10/site-packages/revup/__main__.py", line 17, in _main
    sys.exit(asyncio.run(main()))
  File "/opt/homebrew/Cellar/python@3.10/3.10.6_2/Frameworks/Python.framework/Versions/3.10/lib/python3.10/asyncio/runners.py", line 44, in run
    return loop.run_until_complete(main)
  File "/opt/homebrew/Cellar/python@3.10/3.10.6_2/Frameworks/Python.framework/Versions/3.10/lib/python3.10/asyncio/base_events.py", line 646, in run_until_complete
    return future.result()
  File "/Users/gus/revup/lib/python3.10/site-packages/revup/revup.py", line 357, in main
    return await upload.main(
  File "/Users/gus/revup/lib/python3.10/site-packages/revup/upload.py", line 46, in main
    await topics.query_github()
  File "/Users/gus/revup/lib/python3.10/site-packages/revup/topic_stack.py", line 961, in query_github
    ) = await github_utils.query_everything(
  File "/Users/gus/revup/lib/python3.10/site-packages/revup/github_utils.py", line 301, in query_everything
    reviewers.add(revs["requestedReviewer"]["login"])
TypeError: 'NoneType' object is not subscriptable

[jerry-skydio]

actually supporting Teams is opened as a new feature #76