Documentation for older versions: where?

Expected Behavior

I can still find (browse online, or at least download) the reference documentation for older versions.

Current Behavior

The page https://docs.spring.io/spring-security/reference/ is only showing the documentation for the latest three versions/branches.

Context

We still have some applications running on an extended support release version of Spring Security 5.8 (with Java 8, Java EE, etc.). We are progressively upgrading them to supported releases. However, some very important migration guides are no longer reachable, like the one for 5.8 (which explains important preparation steps to upgrade to Spring Security 6.0) and the one for Spring Security 6.0, which, as far as I remember, was much more exhaustive than the current migration guide in 6.5 reference documentation (which, by the way, does not mention anymore any intermediate steps, like the migration guide in 6.4 does, for example, by mentioning the upgrade steps from 6.1 to 6.2...).

Also the wiki here has broken links:
https://github.com/spring-projects/spring-security/wiki/Spring-Security-6.0-Migration-Guide

As well as the reference documentation of some of the currently supported versions, like:
https://docs.spring.io/spring-security/reference/6.5/migration/index.html
which points to https://docs.spring.io/spring-security/reference/5.8/migration/index.html, which is a 404.

I tried hard to find some links to at least download archived versions of the project, hoping that they contain the full reference documentation, including such migration guides, but I could not succeed.

Can you please advise what is the expected path for users upgrading from older versions?
I opened this as an "enhancement request" here in GitHub, because I think this also impacts the current project version, since the final goal is indeed to upgrade existing applications to the current version of the project, but their reference documentation only explains the migration steps for the immediately preceding version (or is broken anyway, like the aforementioned migration guide for 6.5 version).