Fix the standalone QUICHE build

PiperOrigin-RevId: 574510111

quiche/BUILD.bazel

diff --git a/quiche/BUILD.bazel b/quiche/BUILD.bazel
index 0102f06..201493e 100644
--- a/quiche/BUILD.bazel
+++ b/quiche/BUILD.bazel
@@ -291,6 +291,7 @@
         "@com_google_absl//absl/strings",
         "@com_google_absl//absl/strings:str_format",
         "@com_google_absl//absl/types:optional",
+        "@com_google_absl//absl/types:span",
         "@com_google_googletest//:gtest",
         "@com_google_googleurl//url",
     ],