In the past, we had calls to validateInput in each responder, which in turn calls verifyClientSupported. When the input did not need validation because there was no input, we would instead add direct calls to verifyClientSupported.

However, now validateInput is called implicitly before each responder. As such, verifyClientSupported is also called implicitly, and we don't need any explicit calls to it in responders.

Careful reading of the code. I think this change is relatively safe since I'm just removing a call that already occurs elsewhere