chore: archival of version 0.25, part 4: optimize cleanup

[pepopowitz]

Description

Part of #1173. Follows #2167.

Intended to merge into unsupported/0.25; will never make it to main.

In #2165, I forgot to remove the optimize docs, all of which are unused in this version. This rectifies that.

There are a lot of files, and it will crush your browser when you try to view them. A summary of what's included:

rm -rf ./optimize
rm -rf ./optimize_versioned_docs
rm -rf ./optimize_versioned_sidebars

The presence of these files has zero effect on the published website, as they are ignored by the build anyway. But for clarity, and to avoid someone jumping into this branch and wondering what those files are for, I'm removing them from this branch.

When should this change go live?

• This change is not yet live and should not be merged until {ADD_DATE} (apply hold label or convert to draft PR)?
• There is no urgency with this change.
• This change or page is part of a marketing blog, conference talk, or something else on a schedule.
• This functionality is already available but undocumented.
• This is a bug fix or security concern.

PR Checklist

• I have added changes to the relevant /versioned_docs directory, or they are not for an already released version.
• I have added changes to the main /docs directory (aka /next/), or they are not for future versions.
• My changes require an Engineering review, and I've assigned an engineering manager or tech lead as a reviewer, or my changes do not require an Engineering review.
• My changes require a technical writer review, and I've assigned @christinaausley as a reviewer, or my changes do not require a technical writer review.

[akeller]

Nothing lags the GitHub experience like trying to review a PR with 1.2K files changed 🪦