Fix QUICHE bazel build by adding a missing dependency

PiperOrigin-RevId: 506615639
diff --git a/quiche/BUILD.bazel b/quiche/BUILD.bazel
index edc713e..29d4500 100644
--- a/quiche/BUILD.bazel
+++ b/quiche/BUILD.bazel
@@ -210,6 +210,7 @@
         "@com_google_absl//absl/time",
         "@com_google_absl//absl/types:optional",
         "@com_google_absl//absl/types:span",
+        "@com_google_absl//absl/types:variant",
         "@com_google_googleurl//url",
         "@com_google_quic_trace//quic_trace:quic_trace_cc_proto",
         "@zlib",