modulo interval arithmetic produces incorrect results

The modulo interval arithmetic produces incorrect results. The resulting interval can be _smaller_ than the possible values that could arise at runtime. I have an example on GitHub that produces this incorrect behavior in boost 1.80.

https://godbolt.org/z/36M3za3Px

```c++
safe_signed_range<0, 100, native, loose_trap_policy> a{const_safe_t<50>{}};
safe_signed_range<1, 100, native, loose_trap_policy> b{const_safe_t<100>{}};

auto c = a % b;
```

`c` ends up with an interval of 0 to 0 inclusive, even though it contains the value `50`.