Update to Yarn Berry

[queengooborg]

This PR is intended to be an experiment and demonstration of what we would need to do if we wanted to upgrade to Yarn v2+ (codenamed "Berry"). Note that I don't actually intend for this PR to be merged, at least not unless we want to make the switch (see mdn/mdn-community#61 for discussion on that).

[github-actions]

This pull request has merge conflicts that must be resolved before we can merge this.

[caugner]

So it seems we're running into two issues here:

1. yarn add file:mdn-yari-0.1.6.tgz fails, after having created the file with npm pack:

   yarn add file:mdn-yari-0.1.6.tgz
   ➤ YN0027: file:mdn-yari-0.1.6.tgz@unknown can't be resolved to a satisfying range
   ➤ YN0035: The remote server failed to provide the requested resource
   ➤ YN0035:   Response Code: 404 (Not Found)
   ➤ YN0035:   Request Method: GET
   ➤ YN0035:   Request URL: https://registry.yarnpkg.com/file:mdn-yari-0.1.6.tgz
   

2. yarn install in deployer/aws-lambda/tests/ alternatively changes the yarn.lock file, causing yarn --immutable to always fail.

Possible solutions:

1. Replace npm pack/publish with yarn pack/publish (edit: Did't fix it, but switching to yarn v1 for that part worked.).
2. Use workspaces to link the packages. (edit: Doesn't solve the ever-mutating yarn.lock file.)

[caugner]

@queengooborg Sorry for trashing your branch. I realized only now that I could and should have opened a separate PR targeting your PR.

I don't quite see what we're doing wrong in yari that would cause yarn v3 to either continuously update a hash in yarn.lock, or to bail with this error: Error: While persisting /Users/me/github/mdn/yari/libs/fundamental-redirects/ -> /Users/me/github/mdn/yari/deployer/aws-lambda/content-origin-request/node_modules/@yari-internal/fundamental-redirects EEXIST: file already exists, symlink '../../../../../libs/fundamental-redirects' -> '/Users/me/github/mdn/yari/deployer/aws-lambda/content-origin-request/node_modules/@yari-internal/fundamental-redirects'

Using workspaces doesn't help either. 🤷

[queengooborg]

No worries, please feel free to push to any of my branches here on Yari!

That hash-or-error issue is certainly weird though...

[caugner]

Even without --immutable, yarn isn't happy:

🤦

[github-actions]

This pull request has merge conflicts that must be resolved before we can merge this.

[queengooborg]

Closing this since mdn/mdn-community#108 voted NPM in favor of Yarn Berry.