Remove an obsolete //visibility:private tag (#2070)

PiperOrigin-RevId: 924755156
Change-Id: I60faad5644dbcf53e1ca4a502f1eb4bf4dfd1b87

absl/strings/BUILD.bazel

diff --git a/absl/strings/BUILD.bazel b/absl/strings/BUILD.bazel
index 805cfc2..4c974ce 100644
--- a/absl/strings/BUILD.bazel
+++ b/absl/strings/BUILD.bazel
@@ -435,7 +435,6 @@
     visibility = [
         "//absl:friends",
         "//absl/status:__pkg__",
-        "//visibility:private",
     ],
     deps = [
         ":string_view",