Fix gn_v2 Mac dimensions

Fixes gn_v2 Mac builds not requesting builderless machines. For some
reason, builderless is the default for Linux/Windows but not Mac.

Bug: 385317083
Change-Id: Ibaa3146274f14a77d46d9262b00b877b855ff335
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/263336
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Yuly Novikov <ynovikov@chromium.org>
Auto-Submit: Brian Sheedy <bsheedy@google.com>
diff --git a/infra/config/global/generated/luci/cr-buildbucket.cfg b/infra/config/global/generated/luci/cr-buildbucket.cfg
index e1c5d73..0892ad5 100644
--- a/infra/config/global/generated/luci/cr-buildbucket.cfg
+++ b/infra/config/global/generated/luci/cr-buildbucket.cfg
@@ -2721,7 +2721,7 @@
     builders {
       name: "dawn-mac-x64-builder-rel"
       swarming_host: "chromium-swarm.appspot.com"
-      dimensions: "builder:dawn-mac-x64-builder-rel"
+      dimensions: "builderless:1"
       dimensions: "os:Mac-15"
       dimensions: "pool:luci.chromium.gpu.ci"
       exe {
@@ -2893,7 +2893,7 @@
     builders {
       name: "dawn-mac-x64-sws-rel"
       swarming_host: "chromium-swarm.appspot.com"
-      dimensions: "builder:dawn-mac-x64-sws-rel"
+      dimensions: "builderless:1"
       dimensions: "cpu:x86-64"
       dimensions: "os:Mac-15"
       dimensions: "pool:luci.chromium.gpu.ci"
diff --git a/infra/config/global/gn_standalone_ci.star b/infra/config/global/gn_standalone_ci.star
index 1a17cdb..1e1a07b 100644
--- a/infra/config/global/gn_standalone_ci.star
+++ b/infra/config/global/gn_standalone_ci.star
@@ -47,6 +47,7 @@
     siso_project = siso.project.DEFAULT_TRUSTED,
     siso_remote_jobs = siso.remote_jobs.DEFAULT,
     thin_tester_cores = 2,
+    builderless = True,
 )
 
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