Update yarn to v4

[dddlr]

What is this change?

Update yarn from v1 to v4.

Why are we making this change?

Our version of yarn is five years behind...

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PR checklist

Don't delete me!

I have...

• Updated or added applicable tests
• Updated the documentation in website/
• Inspected the yarn.lock to verify that yarn dedupe works

[changeset-bot]

⚠️ No Changeset found

Latest commit: f351ce4

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

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[dddlr]

yarn dedupe doesn't help with stuff like this, do we care?

[dddlr]

this is not good...

[kylorhall-atlassian]

this is not good...

Sounds fun, good luck! Let me know if you get it green 🤣