This is being emitted with [GCC 10.2.1](https://packages.debian.org/bullseye/g++-arm-linux-gnueabihf), in some CI jobs: i.e https://github.com/bitcoin/bitcoin/pull/25972/checks?check_run_id=12423693655, or https://github.com/bitcoin/bitcoin/pull/25972/checks?check_run_id=12423693651 (where we actually turn on all our warning flags with depends builds).
```bash
In file included from test/miniscript_tests.cpp:19:
./script/miniscript.h:1197:71: error: comparison of integers of different signs: 'typename iterator_traits<int *>::difference_type' (aka 'int') and 'const uint32_t' (aka 'const unsigned int') [-Werror,-Wsign-compare]
                    return std::count(subs.begin(), subs.end(), true) >= node.k;
                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^  ~~~~~~
test/miniscript_tests.cpp:346:34: note: in instantiation of function template specialization 'miniscript::Node<CPubKey>::IsSatisfiable<(lambda at test/miniscript_tests.cpp:346:48)>' requested here
        bool satisfiable = node->IsSatisfiable([](const Node&) { return true; });
                                 ^
1 error generated.
```

cc @darosior 
constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, Fragment::WRAP_C, Vector(std::move(constructed.back())));
            break;
        }
        case ParseContext::DUP_IF: {
            constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, Fragment::WRAP_D, Vector(std::move(constructed.back())));
            break;
        }
        case ParseContext::NON_ZERO: {
            constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, Fragment::WRAP_J, Vector(std::move(constructed.back())));
            break;
        }
        case ParseContext::ZERO_NOTEQUAL: {
            constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, Fragment::WRAP_N, Vector(std::move(constructed.back())));
            break;
        }
        case ParseContext::VERIFY: {
            script_size += (constructed.back()->GetType() << "x"_mst);
            constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, Fragment::WRAP_V, Vector(std::move(constructed.back())));
            break;
        }
        case ParseContext::WRAP_U: {
            constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, Fragment::OR_I, Vector(std::move(constructed.back()), MakeNodeRef<Key>(internal::NoDupCheck{}, Fragment::JUST_0)));
            break;
        }
        case ParseContext::WRAP_T: {
            constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, Fragment::AND_V, Vector(std::move(constructed.back()), MakeNodeRef<Key>(internal::NoDupCheck{}, Fragment::JUST_1)));
            break;
        }
        case ParseContext::AND_B: {
            BuildBack(Fragment::AND_B, constructed);