Update com_google_riegeli digest to f56a831

Author: renovate[bot]

bazel/zetasql_deps_step_2.bzl

@@ -187,9 +187,9 @@ py_library(
             http_archive(
                 name = "com_google_riegeli",
                 # Commit from 2022-02-16
-                url = "https://github.com/google/riegeli/archive/934428f44a6d120cb6c065315c788aa3a1be6b66.tar.gz",
-                sha256 = "a54dafa634db87723db106bc44ef365b1b442d8862aafbeb5f1d2e922049e587",
-                strip_prefix = "riegeli-934428f44a6d120cb6c065315c788aa3a1be6b66",
+                url = "https://github.com/google/riegeli/archive/f56a831267862161530e124e45648013b0e95186.tar.gz",
+                sha256 = "6798e7e0a68bf580c8ea051fbbc35ace23bbd0315e853371afa16a499519d588",
+                strip_prefix = "riegeli-f56a831267862161530e124e45648013b0e95186",
             )
     if evaluator_deps:
         # Differential Privacy