Use default minimal ANSI locale.

Despite requesting UTF-8, MinGW appears to have been using
the 'C' locale the whole time, so we should enforce that here
even if UCRT's setlocale() actually works as advertised.

src/main.cpp

@@ -102,8 +102,7 @@ main(int argc, char *argv[]) {
   task_pool_util::TaskPool::task_id_t force_shutdown = nullptr;
 
 #ifdef _WIN32
-  // Switch default C standard library locale to UTF-8 on Windows 10 1803+
-  setlocale(LC_ALL, ".UTF-8");
+  setlocale(LC_ALL, "C");
 #endif
 
 #pragma GCC diagnostic push