During the development of the action module, the configuration entity moved from the action module to the system module. However, the configuration entity prefix was still action.action. As a result, if you uninstalled the action module and had the views module enabled, you would suddenly lose functionality on admin/people.
Consequently, the system module's configured action entity was renamed from
For contributed modules, yml files that define actions should also use the
system.action.foo.yml naming pattern.