Meta::ZeroClickInfo: simplify supported attributes check.

Streamline to a single code path for checking key/value pairs.

The hash key look up will be faster than checking against every
element in the array from the function call each time.

On the other hand, even though I got here somehow, I can't actually see
where it will get run.
I'm confused how `@_` will work if set to a `HASH`?  Is it assumed if it's not a hashref that it's a hash?