By default, disable all caching in tests, to preserve test independence.
In order to enable caching, inherit from CacheSetupMixin, and specify
which cache configuration is needed.

[EV-32]

Instead, use a class attribute to define test behavior. This allows for
easier addition of new mixins over time.

More accurately, this creates a 4th shard because the
last shard is always the default.

More accurately, this creates a 4th shard because the
last shard is always the default.

MA-1368

ECOM-2972