Fix OSS QUICHE build.

Add `@com_google_absl//absl/strings:cord` depencency to `//quiche:moqt_core`.

PiperOrigin-RevId: 882161144

quiche/BUILD.bazel

diff --git a/quiche/BUILD.bazel b/quiche/BUILD.bazel
index c5b2064..1792111 100644
--- a/quiche/BUILD.bazel
+++ b/quiche/BUILD.bazel
@@ -430,6 +430,7 @@
         "@com_google_absl//absl/status",
         "@com_google_absl//absl/status:statusor",
         "@com_google_absl//absl/strings",
+        "@com_google_absl//absl/strings:cord",
         "@com_google_absl//absl/strings:str_format",
         "@com_google_absl//absl/time",
         "@com_google_absl//absl/types:span",