Move quic_client_factory.h into cross-platform tools target.

It's used in quic_toy_client, which is used as a base for Chrome-specific client tool.

PiperOrigin-RevId: 563492310
diff --git a/build/source_list.bzl b/build/source_list.bzl
index 16ab6f1..8b4383f 100644
--- a/build/source_list.bzl
+++ b/build/source_list.bzl
@@ -697,6 +697,7 @@
     "quic/tools/fake_proof_verifier.h",
     "quic/tools/quic_backend_response.h",
     "quic/tools/quic_client_base.h",
+    "quic/tools/quic_client_factory.h",
     "quic/tools/quic_memory_cache_backend.h",
     "quic/tools/quic_name_lookup.h",
     "quic/tools/quic_simple_client_session.h",
@@ -987,7 +988,6 @@
     "quic/masque/masque_utils.h",
     "quic/platform/api/quic_udp_socket_platform_api.h",
     "quic/tools/quic_client_default_network_helper.h",
-    "quic/tools/quic_client_factory.h",
     "quic/tools/quic_default_client.h",
     "quic/tools/quic_epoll_client_factory.h",
     "quic/tools/quic_server.h",