gh-108724: Fix _PySemaphore compile error on WASM

Some WASM platforms have POSIX semaphores, but not sem_timedwait.

Author: colesbury

Include/internal/pycore_semaphore.h

@@ -20,7 +20,8 @@
 #   error "Require native threads. See https://bugs.python.org/issue31370"
 #endif
 
-#if defined(_POSIX_SEMAPHORES) && (_POSIX_SEMAPHORES+0) != -1
+#if (defined(_POSIX_SEMAPHORES) && (_POSIX_SEMAPHORES+0) != -1 && \
+        defined(HAVE_SEM_TIMEDWAIT))
 #   define _Py_USE_SEMAPHORES
 #   include <semaphore.h>
 #endif