chore: import upstream snapshot with attribution

third_party/skcms/BUILD

@@ -0,0 +1,3 @@
+# This empty BUILD file is required to make Bazel treat this directory as a package.
+
+# copybara:uncomment package(default_applicable_licenses = ["//tensorflow:license"])

third_party/skcms/skcms.BUILD.bazel

@@ -0,0 +1,18 @@
+licenses(["notice"])
+
+package(default_visibility = ["//visibility:public"])
+
+exports_files(["LICENSE"])
+
+cc_library(
+    name = "skcms",
+    srcs = ["skcms.cc"] + glob([
+        "src/*.h",
+        "src/*.cc",
+    ]),
+    hdrs = ["skcms.h"],
+    copts = [
+        "-DSKCMS_PORTABLE",
+        "-DSKCMS_STANDALONE",
+    ],
+)

third_party/skcms/workspace.bzl

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+"""Point to the skcms repo on GitHub."""
+
+load("//third_party:repo.bzl", "tf_http_archive", "tf_mirror_urls")
+
+def repo():
+    tf_http_archive(
+        name = "skcms",
+        strip_prefix = "skcms-2025_09_16",
+        sha256 = "08c45dff8ede1b56a6e7d1e9fdaf113dd91ab28ddcbcf696229b683e5e9af45a",
+        urls = tf_mirror_urls("https://github.com/google/skcms/archive/refs/tags/2025_09_16.tar.gz"),
+        build_file = "//third_party/skcms:skcms.BUILD.bazel",
+    )