The default AIL templates for Windows, which are built using the ASPL compiler and GCC in the CI/CD pipeline, currently depend on libwinpthread-1.dll as they dynamically link to it (objdump -p program.exe).
This goes against the idea of standalone executable templates that should work on all Windows computers, regardless of the software installed there. Thus, I would classify this as a kind of bug.
Possible solutions would be to use zig cc to build the templates in the toolchain, but iirc this led to worse performance or other problems. We could also just try to tell GCC to not link to this library and instead use the standard Windows threading DLLs, but I don't really know how this could be done.