--- upgrade: - Removes the sphinxcontrib-seqdiag dependency as the Pillow upgrade to version 10.x (from OpenStack upper constraints) breaks its usage. seqdiag has not been maintained for the last 3 years, hence the upgrade causes it to break. In the ironic docs (source) rst files, adds references to svg files, and keeps the svg files in the doc/source/images/ directory, alongside their associated .diag files as backup.