Fix Kernel.p and Kernel.pp type with no argument

[tompng]

Kernel.p(T) returns T, Kernel.p(*more_than_two) returns array, Kernel.p() retuns nil.
I added the missing definition () -> nil.

I think (*untyped arg0) -> Array[untyped] conflicts with (T arg0) -> T and () -> nil, so I changed it to (untyped, untyped, *untyped) -> Array[untyped]

# I referenced core/module.rbs
class Module < Object
  def public: () -> nil
            | (Symbol method_name) -> Symbol
            | (Symbol, Symbol, *Symbol method_name) -> Array[Symbol]
            | ...
end

[ksss]

It appears that this line is the difference and the test is failing.

[tompng]

Thanks, I remove it