gh-133342: Remove sym_is_const and sym_has_type

[tomasr8]

• Simplify patterns such as

if (sym_is_const(ctx, flag)) {
  PyObject *value = sym_get_const(ctx, flag);
  // use value
}

into

PyObject *value = sym_get_const(ctx, flag);
if (value) {
  // use value
}

• Remove sym_is_const and sym_has_type. They can be replaced by sym_get_const and sym_get_type respectively. This part is more of an exploration, these functions might still be useful in some situations. If we do decide to keep them, we can still simplify them quite a bit.

Check out the issue for more context!

• Issue: Simplify _Py_uop_sym_is_const #133342

[Fidget-Spinner]

LGTM. But let's wait for #132733 to merge, then your diff can be smaller as half of the manual constants will be gone :).