test(owners): provoke test failure for nodejs/node repo owners tests
test(owners): provoke test failure for nodejs/node repo owners tests

Turns out the nodejs/node repo owners functionality has been broken
for quite some time. When upgrading `@octokit/rest` and avoiding a
deprecation warning back in November 2020, the owners functionality
was broken.

The culprit seems to the `.number -> .pull_number` transition
in https://github.com/nodejs/github-bot/commit/7b4ac859952163479b2afe159cf0ff29416b37bb,
especially related to listing changes files in a PR when figuring out
which owners to ping.

This microscopic change, removing the `.pull_number` field from the
options used in `./test/unit/node-repo-owners.test.js` surfaces the
issue and correctly causes tests to break.

`options.pull_number` is NOT part of the options being sent through the
code base when a GitHub webhook event is emitted.

By removing that field from the `options` used while testing, certain
test expectations don't pass, which they should at this point, because
some code has to be adjusted first.

nodejs/github-bot