Update registry paths on Archives page

When we launch the site and start cutting releases in the https://gitlab.com/gitlab-org/technical-writing-group/gitlab-docs-hugo project, the paths for the released Docker images will change. This affects this page: https://new.docs.gitlab.com/archives/

Unfortunately this means we have 3 possible paths for a Docker image:

• Versions before 15.6: registry.gitlab.com/gitlab-org/gitlab-docs:$VER
• Versions 15.6 to HUGO_LAUNCH_VERSION: registry.gitlab.com/gitlab-org/gitlab-docs/archives:$VER
• Versions newer than HUGO_LAUNCH_VERSION: registry.gitlab.com/gitlab-org/gitlab-docs/archives:$VER

Template: https://gitlab.com/gitlab-org/technical-writing-group/gitlab-docs-hugo/-/blob/main/themes/gitlab-docs/layouts/shortcodes/archiveList.html?ref_type=heads

We can use this existing variable to handle when the format shifts to the new one: https://gitlab.com/gitlab-org/technical-writing-group/gitlab-docs-hugo/-/blob/main/themes/gitlab-docs/src/utils/constants.js#L1

It might be easier to just create a static map of the versions/endpoints rather than trying to compare versions using Hugo template functions.