chore(internal): add yarn deduplicate script, cleanup lock

[Simek]

Motivation

This small PR deduplicates yarn lock file using yarn-deduplicate package. It also adds the deduplicate script as lock:update command. Let me know if you would like also to see this in postinstall (to automatically optimize lock on every dependency change).

You can read more about what the script does and why it's important in the Readme section:

• https://github.com/atlassian/yarn-deduplicate#duplicated-packages

This might also fix the problems with the old, pinned packages, which are lately emerging in the repository (see related PRs).

Have you read the Contributing Guidelines on pull requests?

Yes.

Test Plan

Successful build and run of Docusuaurus V2 website on my local machine.

Related PRs

• chore(v2): upgrade dependencies #3727
• chore(v2): downgrade babel-plugin-dynamic-import-node to 2.3.0 #3734

[netlify]

Deploy preview for docusaurus-2 ready!

Built without sensitive environment variables with commit 3fe54a3

https://deploy-preview-3738--docusaurus-2.netlify.app

[slorber]

thanks, I'm ok to have this on postinstall

[slorber]

can it messup with yarn 2 users?

[slorber]

yarn lock conflict now :)

[Simek]

@slorber Conflict has been created after the merge of #3716. Might be wise to rerun the lock script after that merge on this branch.