mac: try to make new fyi bot actually be a mac

Generated files in infra/config/generated by running:

    lucicfg generate infra/config/main.star

TBR=mark@chromium.org

Bug: 1098454
Change-Id: I8096cef8111688010492184deccb1c9f85dafaf3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2261369Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#781610}

infra/config/generated/cr-buildbucket.cfg

@@ -11716,18 +11716,17 @@ buckets {
       name: "mac-arm64"
       swarming_host: "chromium-swarm.appspot.com"
       swarming_tags: "vpython:native-python-wrapper"
-      dimensions: "builderless:1"
+      dimensions: "builder:mac-arm64"
       dimensions: "cores:8"
       dimensions: "cpu:x86-64"
-      dimensions: "os:Ubuntu-16.04"
+      dimensions: "os:Mac"
       dimensions: "pool:luci.chromium.ci"
-      dimensions: "ssd:0"
       recipe {
         name: "chromium"
         cipd_package: "infra/recipe_bundles/chromium.googlesource.com/chromium/tools/build"
         cipd_version: "refs/heads/master"
         properties_j: "$build/chromium_tests:{\"bucketed_triggers\":true}"
-        properties_j: "$build/goma:{\"enable_ats\":true,\"rpc_extra_params\":\"?prod\",\"server_host\":\"goma.chromium.org\"}"
+        properties_j: "$build/goma:{\"rpc_extra_params\":\"?prod\",\"server_host\":\"goma.chromium.org\"}"
         properties_j: "$kitchen:{\"devshell\":true,\"git_auth\":true}"
         properties_j: "mastername:\"chromium.fyi\""
       }

infra/config/subprojects/chromium/ci.star

@@ -658,6 +658,7 @@ ci.fyi_builder(
         short_name = 'arm64',
     ),
     main_console_view = None,
+    os = os.MAC_ANY,
 )
 
 ci.fyi_ios_builder(