stable_t<hybrid_adapter> test times out with MSVC 2022 in Debug

[Morwenn]

See this job: https://github.com/Morwenn/cpp-sort/actions/runs/16099277451/job/45426259775

So far I've got no idea why, which is a bit of a bummer, it worked fine with MSVC 2019, and it works fine in Release mode. Right now I'm inclined to blame MSVC for a codegen bug, but history has shown that it was often my fault and I believe that it occurs around a tricky piece of metaprogramming craft.