Split quic_client_lib into quic_client_lib and quic_epoll_client_lib

Deprecate the latter, and restrict the visibility to it.

PiperOrigin-RevId: 471390662
diff --git a/quiche/quic/core/http/end_to_end_test.cc b/quiche/quic/core/http/end_to_end_test.cc
index c0c31de..f765afe 100644
--- a/quiche/quic/core/http/end_to_end_test.cc
+++ b/quiche/quic/core/http/end_to_end_test.cc
@@ -67,7 +67,6 @@
 #include "quiche/quic/test_tools/server_thread.h"
 #include "quiche/quic/test_tools/web_transport_test_tools.h"
 #include "quiche/quic/tools/quic_backend_response.h"
-#include "quiche/quic/tools/quic_client.h"
 #include "quiche/quic/tools/quic_memory_cache_backend.h"
 #include "quiche/quic/tools/quic_server.h"
 #include "quiche/quic/tools/quic_simple_client_stream.h"