remove type specifiers before conceptify

[jimkoen]

Something like a typed concept is ill formed and doesn't make sense anyway since it's not a type.

Problem:

When using conceptify on Clang 16.0.6, compilation will fail with:

te.hpp:571:14: error: ISO C++ does not permit the 'bool' keyword after 'concept'
concept bool var = requires {
             ^
te.hpp:577:14: error: ISO C++ does not permit the 'bool' keyword after 'concept'
concept bool conceptify = requires {

Solution:

Remove the bool keyword in front of the two concepts, as they are not types.