Apparently Object.keys on NamedNodeMap work differently with googlebot :-(
There are not tests since we don't have a way to write tests for googlebot,
but I did manually verify that after this fix googlebot correctly renders
several of the previously broken pages.
Fixes#21272
PR Close#21305
These utils support flexible, natural attribute interpretation as applied to code-example and code-pane. Then apply those utils to code-example and live-example