Release 1.5.4.

[mike-jumper]

This change:

• Marks 1.5.4 as released.
• Updates the top-level symbolic links to the latest documentation.
• Marks the previous release (1.5.3) as archived.

We'll still need to hold off on actually deploying these changes until 2023-12-08 17:00:24 -0800, as that will be 24 hours since the release artifacts were deployed (and the mirrors need roughly 24 hours to sync). From http://www.apache.org/dev/release.html#release-announcements:

Please ensure that you wait at least 24 hours after uploading a new release before updating the project download page and sending the announcement email(s). This is so that mirrors have sufficient time to catch up. (For time-critical security releases, the download pages script supports bypassing this requirement.)

Also, from http://www.apache.org/dev/release-publishing.html#sync-delay:

Apache uses svnpubsub internally and rsync mirrroring externally. Files committed to the Subversion repository at https://dist.apache.org/repos/dist/ are automatically copied, using svnpubsub, to www.apache.org , and then the external mirrors pick up the files from www.apache.org. It may take up to 24 hours or more for a newly published release to be sync'd to all mirrors. Mirrors have their own schedules. Mirrors are required to check at least once a day, but most will check for updates 2 to 4 times per day.