Link error of call get_system_scheduler()

Description:

I'm encountering an issue when using exec::get_system_scheduler() in my code. The code compiles successfully when using exec::static_thread_pool, but it fails when using exec::get_system_scheduler().

Code:

void l3_scheduler() {
  stdexec::scheduler auto sch = exec::get_system_scheduler();
  stdexec::sender auto computation =
    stdexec::schedule(sch) | stdexec::then([] {
      fmt::println("Hello, from a different thread");
    });
  stdexec::sync_wait(std::move(computation));
}

The error message is as follows:

"__query_system_context_interface(__uuid const&)", referenced from:
    l3_scheduler() in main.cpp.o
 ld: symbol(s) not found for architecture arm64

The following code works without issues:

exec::static_thread_pool pool(8);
auto sch = pool.get_scheduler();

Environment:

• macOS: M1 MacBook Pro (arm64)

• Ubuntu: x86 architecture

• Compiler: clang++-19

Steps to Reproduce:

1. Use stdexec::scheduler with exec::get_system_scheduler().

2. Attempt to compile the code on macOS M1 or Ubuntu (x86).

3. Observe the linker error.

No source files or tests are named. Start by reproducing the linker failure with exec::get_system_scheduler() on the listed platforms and compare it with exec::static_thread_pool; done means the provided scheduler example links and runs without the missing __query_system_context_interface symbol.