CCC fails to recognize bool, true, and false in C23 mode

Description:
When compiling the following code with CCC using -std=c23:

```
bool is_even(int number) {
return number % 2 == 0;
}
```

the compiler fails to compile due to `bool`, `true`, and `false` being unrecognized. The same code compiles correctly with GCC and Clang in C23 mode.

Steps to Reproduce:

Save the code to a file test.c.

Compile with CCC using:

`ccc -std=c23 test.c`

Expected Behavior:
The compiler should accept `bool`, `true`, and `false` as valid C23 keywords.

Actual Behavior:
The compiler reports unknown type/identifier errors for `bool`, `true`, and `false.