Update static sitemap

The file has last been updated with a site scan in 2020, so it is about
time.

The script used to generate this has been updated with [0], so Yoga and
older series are no longer contained in the index.

[0] https://review.opendev.org/c/openstack/openstack-doc-tools/+/914614

Change-Id: I5b624122f55571d9e2413b73122295ab058095ae