"Build and deploy documentation" workflow failing

[cgay]

The doc build itself is getting warnings that should be considered fatal:

[sphinx-action] Running: ['make', 'html', '-e']
Warning: toctree contains reference to nonexisting document 'sphinx-extensions/documentation/source/index'
Warning: toctree contains reference to nonexisting document 'package/index'
Warning: document isn't included in any toctree
Warning: unknown document: '../package/http/server/quickstart/index'
Warning: unknown document: '../package/index'
Warning: unknown document: '../package/dylan-tool/index'
Warning: unknown document: '../package/index'
[sphinx-action] Build succeeded with 7 warnings

The "Deploy to GH pages" phase is getting permission errors:

/usr/bin/chmod -R +rw /home/runner/work/opendylan/opendylan/documentation/website/build/html
/usr/bin/chmod: changing permissions of '/home/runner/work/opendylan/opendylan/documentation/website/build/html': Operation not permitted
...many more permissions errors...