[clang-tidy] Skip parentheses in `readability-make-member-function-const`

The checker should ignore parentheses when looking whether the
function should be marked as `const`.

Fixes https://github.com/llvm/llvm-project/issues/52838

Reviewed By: mgehre-amd, njames93

Differential Revision: https://reviews.llvm.org/D122075