archive(8.2) isolation: pt 2, reviewable steps

[pepopowitz]

Note: this PR currently targets unsupported/8.2. These changes will not make it intomain.

Description

Part of #4527.

This PR includes the reviewable steps for isolating an 8.2 website. After this merges, I'll publish a standalone 8.2 release.

Most of the steps in this PR were automated, but the last couple are manual:

Progress

• update version archival process to account for infrastructure changes (the changes from chore: update version archival process to account for infrastructure changes #4624, which were not in main when I created unsupported/8.2.)
• exclude all other versions from the main version file
• update version numbers for isolation
• exclude all other versions from the optimize version file
• prevent unsupported site from being crawled
• fix Dockerfile for local debugging
• update theme components
• update CI workflows
• update docusaurus config
• configure Optimize docs instance
• ------- above this was handled automatically; below is manual ---------
• fix incorrect links
• fix htaccess rules

When should this change go live?

• This is a bug fix, security concern, or something that needs urgent release support.
• This is already available but undocumented and should be released within a week.
• This on a specific schedule and the assignee will coordinate a release with the DevEx team. (apply hold label or convert to draft PR)
• This is part of a scheduled alpha or minor. (apply alpha or minor label)
• There is no urgency with this change and can be released at any time.

PR Checklist

• My changes are for an already released minor and are in /versioned_docs directory.
• My changes are for the next minor and are in /docs directory (aka /next/).

• My changes require an Engineering review, and I've assigned the Engineering DRI or delegate.

• My changes require a technical writer review, and I've assigned @camunda/tech-writers as a reviewer.

• My changes require a docs infrastructure review.

[pepopowitz]

Removing this entire section, because only 1 of 3 links in here applies to this version.

[akeller]

This looks good, however, I just skimmed the link changes.