deps: upgrade npm to 7.0.0-rc.0

[darcyclarke]

It's been awhile... reference to the 7.0.0-rc.0 specific release notes: https://github.com/npm/cli/releases/tag/v7.0.0-rc.0 & corresponding v7 CHANGELOG.md

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/33316/
CITGM: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/2487/

[Trott]

This causes test/parallel/test-npm-version.js to fail. A seeming purpose of that test is to make sure we don't land npm rc's/betas/etc. Rather than altering the test, I think the thing to do is add an entry to test/parallel/parallel.status that turns the test yellow when it fails rather than red. This way, there's a clear indication in the CI that the code is not yet ready for release, but it won't stop other code from landing due to CI failing.

I think it would look like this:

[true] # This section applies to all platforms
# We temporarily have a npm rc. Allow test-npm-version to fail until it is
# removed.
# https://github.com/nodejs/node/pull/35447
test-npm-version: FLAKY

By using FLAKY and not PASS,FLAKY, I think the test will be required to fail. That will remind us to undo this when npm 7 is released for reals.

Another (perhaps simpler?) approach might be to move the test to test/known_issues where it will also be required to fail.

[Trott]

#35447 (comment)

[MylesBorins]

Closing in lieu of #35474