Description

Part of #2184.

Note: This PR will be merged into the unsupported/0.26 branch, and will never make it to main.

Note: This PR will not go green. There are manual cleanup steps coming in a future PR that will make it go green.

Continues the process of archival/isolation for version 0.26. Includes the following steps, which a computer did for me:

1. Exclude all other versions from version manifest file
2. Prevent the 0.26 site from being crawled
3. Fix the Dockerfile for local debugging
4. (new!) Updates the swizzled theme components for the isolated version. Note that a separate PR will be opened for the new script that did this for me.

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.