chore: update lerna to v6.2.0

[AgentEnder]

Pre-flight checklist

• I have read the Contributing Guidelines on pull requests.
• [na] If this is a code change: I have written unit tests and/or added dogfooding pages to fully verify the new behavior.
• [na] If this is a new API or substantial change: the PR has an accompanying issue (closes #0000) and the maintainers have approved on my working plan.

Motivation

Bumps Lerna to latest v6 as a stepping stone for enabling Nx. Discussed with @yangshun and @slorber. See #8318

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[github-actions]

⚡️ Lighthouse report for the deploy preview of this PR

URL	Performance	Accessibility	Best Practices	SEO	PWA	Report
/	🟠 55	🟢 97	🟢 100	🟢 100	🟢 90	Report
/docs/installation	🟠 80	🟢 100	🟢 100	🟢 100	🟢 90	Report

[slorber]

Thanks 👍

Tried this locally and it seems to work as before