Update boringssl digest to b28d2e8

Author: renovate[bot]

bazel/zetasql_deps_step_2.bzl

@@ -218,10 +218,10 @@ py_library(
                 name = "boringssl",
                 # Commit from 2021-11-01
                 urls = [
-                    "https://github.com/google/boringssl/archive/4fb158925f7753d80fb858cb0239dff893ef9f15.tar.gz",
+                    "https://github.com/google/boringssl/archive/b28d2e8fa0be6c0b4e584e99d0c8dfbaf38449cc.tar.gz",
                 ],
-                sha256 = "e168777eb0fc14ea5a65749a2f53c095935a6ea65f38899a289808fb0c221dc4",
-                strip_prefix = "boringssl-4fb158925f7753d80fb858cb0239dff893ef9f15",
+                sha256 = "c9d22fb4f15d22d8fd152625a10b7b3ea3631d8f8b8d6775a0ed17a9d48d65f4",
+                strip_prefix = "boringssl-b28d2e8fa0be6c0b4e584e99d0c8dfbaf38449cc",
             )
 
         # Farmhash