Add darwin_arm64 and darwin_arm64e to c-ares' config settings

This fixes Bazel selecting the wrong source for `cares` when building
with `--cpu=darwin_arm64` or `--cpu=darwin_arm64e` (it was selecting the
source in the default condition, which is for Linux).

We're having the same patch in Bazel
(1782f0ae75;
it was using an older grpc release). Fixing this here so we can remove
the patch in the next update.

third_party/cares/cares.BUILD

@@ -10,6 +10,16 @@ config_setting(
     values = {"cpu": "darwin_x86_64"},
 )
 
+config_setting(
+    name = "darwin_arm64",
+    values = {"cpu": "darwin_arm64"},
+)
+
+config_setting(
+    name = "darwin_arm64e",
+    values = {"cpu": "darwin_arm64e"},
+)
+
 config_setting(
     name = "windows",
     values = {"cpu": "x64_windows"},
@@ -99,6 +109,8 @@ copy_file(
         ":watchos_arm64_32": "@com_github_grpc_grpc//third_party/cares:config_darwin/ares_config.h",
         ":darwin": "@com_github_grpc_grpc//third_party/cares:config_darwin/ares_config.h",
         ":darwin_x86_64": "@com_github_grpc_grpc//third_party/cares:config_darwin/ares_config.h",
+        ":darwin_arm64": "@com_github_grpc_grpc//third_party/cares:config_darwin/ares_config.h",
+        ":darwin_arm64e": "@com_github_grpc_grpc//third_party/cares:config_darwin/ares_config.h",
         ":windows": "@com_github_grpc_grpc//third_party/cares:config_windows/ares_config.h",
         ":android": "@com_github_grpc_grpc//third_party/cares:config_android/ares_config.h",
         "//conditions:default": "@com_github_grpc_grpc//third_party/cares:config_linux/ares_config.h",