Issue #27652: Expose ESHUTDOWN conditionally

ESHUTDOWN is also exposed conditionally in Modules/errnomodule.c.

Patch by Ed Schouten.
diff --git a/Objects/exceptions.c b/Objects/exceptions.c
index d97d569..f829d32 100644
--- a/Objects/exceptions.c
+++ b/Objects/exceptions.c
@@ -2604,7 +2604,9 @@
     ADD_ERRNO(BlockingIOError, EWOULDBLOCK);
     POST_INIT(BrokenPipeError);
     ADD_ERRNO(BrokenPipeError, EPIPE);
+#ifdef ESHUTDOWN
     ADD_ERRNO(BrokenPipeError, ESHUTDOWN);
+#endif
     POST_INIT(ChildProcessError);
     ADD_ERRNO(ChildProcessError, ECHILD);
     POST_INIT(ConnectionAbortedError);