Cord does not need its str_format dependency

Fixes #1360

PiperOrigin-RevId: 504850733
Change-Id: Ifa1e83d0c703ed69c969a12076db474caec9d496

absl/strings/BUILD.bazel

@@ -457,7 +457,6 @@ cc_library(
         ":cordz_update_scope",
         ":cordz_update_tracker",
         ":internal",
-        ":str_format",
         ":strings",
         "//absl/base",
         "//absl/base:config",

absl/strings/cord.cc

@@ -48,7 +48,6 @@
 #include "absl/strings/internal/cordz_update_tracker.h"
 #include "absl/strings/internal/resize_uninitialized.h"
 #include "absl/strings/str_cat.h"
-#include "absl/strings/str_format.h"
 #include "absl/strings/str_join.h"
 #include "absl/strings/string_view.h"