Remove ConfigEntityListBuilder::getDefaultOperations() override

Problem/Motivation

See discussion in 🐛 Views entity operations lack cacheability support, resulting in incorrect dropbuttons Needs work .

ConfigEntityListBuilder and all its subclasses override ::getDefaultOperations(), we should try to remove the override, or at least if not document why it's done.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

Introduced terminology

API changes

Data model changes

Release notes snippet