ServiceNow plugin 1.2.0 it exports the ServicePage now as EntityServicenowContent

It also provides a isServicenowAvailable util function to decide if the tab should be displayed or not.

See https://github.com/backstage/community-plugins/pull/5265 and https://github.com/backstage/community-plugins/pull/5265#pullrequestreview-3198876647

This changes should be adopted in our documentation.

Precondtion:

There should be a overlay repo release for the new servicenow plugin (1.2.0 or higher)