It didn't really make any sense to have custom conditions that
depend on the presence or absence of beans of type Function,
Supplier, Consumer because the actual endpoints are derived
from the FunctionCatalog (which might not be based on
bean definitions). This approach is far simpler, and
reduces the amount of custom code in the stream binder.
The spring.cloud.function.stream.supplier.enabled flag
is awkward, so we should try and find a way to avoid that.
There's also no reason it should need to be set in the
deployer tests.