Tag the CC tests related to the remote executor with `nomacos`.

This change should enable the MacOS presubmit to succeed.

PiperOrigin-RevId: 410926931

tensorflow_federated/cc/core/impl/executor_stacks/BUILD

@@ -81,6 +81,7 @@ cc_library(
 tff_cc_test_with_tf_deps(
     name = "remote_stacks_test",
     srcs = ["remote_stacks_test.cc"],
+    tags = ["nomacos"],
     deps = [
         ":remote_stacks",
         "//tensorflow_federated/cc/common_libs:oss_test_main",

tensorflow_federated/cc/core/impl/executors/BUILD

@@ -358,6 +358,7 @@ tff_cc_test_with_tf_deps(
     name = "remote_executor_test",
     timeout = "short",
     srcs = ["remote_executor_test.cc"],
+    tags = ["nomacos"],
     tf_deps = [
         "@org_tensorflow//tensorflow/cc:array_ops",
         "@org_tensorflow//tensorflow/cc:math_ops",