chore(deps): update com_grail_bazel_toolchain digest to 756b3db (#135)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

WORKSPACE.bazel

@@ -15,9 +15,9 @@ hedron_compile_commands_setup()
 
 http_archive(
     name = "com_grail_bazel_toolchain",
-    sha256 = "ece2fa0a36a457445cb18db3be09bf8a304fe41d30acb7a3c69a070f02f0dc29",
-    strip_prefix = "bazel-toolchain-b193952cdb9dd3134f51159d820614ff32dba079",
-    url = "https://github.com/grailbio/bazel-toolchain/archive/b193952cdb9dd3134f51159d820614ff32dba079.zip",
+    sha256 = "2db3970d6ba1b9bf4cff4fdab3bf0c13be30bd29a81031dbfd22a060183379a1",
+    strip_prefix = "bazel-toolchain-756b3dbe9582503e0f671188a5aa4dec3b9710bf",
+    url = "https://github.com/grailbio/bazel-toolchain/archive/756b3dbe9582503e0f671188a5aa4dec3b9710bf.zip",
 )
 
 load("@com_grail_bazel_toolchain//toolchain:deps.bzl", "bazel_toolchain_dependencies")