Pin mac-rel to use Mac 10.13 machines.

Using MAC_ANY caused it to pick up Mac 10.15 machines, which don't
support the GN args currently used by mac-rel. Which causes them to fail
quickly and then get re-used frequently. Until we determine the solution
going forward, changing the os dimension will get the builds back to
green.

# mac-rel is broken, this change will fix it

Bug: 1073694, 1073965
Change-Id: I2620c570c443be89f27ace27cbbd9c3c25cd4010
No-Try: True
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2163151
Commit-Queue: Garrett Beaty <gbeaty@chromium.org>
Auto-Submit: Garrett Beaty <gbeaty@chromium.org>
Reviewed-by: Ben Pastene <bpastene@chromium.org>
Cr-Commit-Position: refs/heads/master@{#762008}

infra/config/generated/cr-buildbucket.cfg

@@ -24694,7 +24694,7 @@ buckets: <
       swarming_tags: "vpython:native-python-wrapper"
       dimensions: "builderless:1"
       dimensions: "cpu:x86-64"
-      dimensions: "os:Mac"
+      dimensions: "os:Mac-10.13"
       dimensions: "ssd:1"
       recipe: <
         name: "chromium_trybot"
@@ -27176,7 +27176,7 @@ buckets: <
       swarming_tags: "vpython:native-python-wrapper"
       dimensions: "builderless:1"
       dimensions: "cpu:x86-64"
-      dimensions: "os:Mac"
+      dimensions: "os:Mac-10.13"
       dimensions: "pool:luci.chromium.try"
       dimensions: "ssd:1"
       recipe: <
@@ -28835,7 +28835,7 @@ buckets: <
       swarming_tags: "vpython:native-python-wrapper"
       dimensions: "builderless:1"
       dimensions: "cpu:x86-64"
-      dimensions: "os:Mac"
+      dimensions: "os:Mac-10.13"
       dimensions: "pool:luci.chromium.try"
       dimensions: "ssd:1"
       recipe: <

infra/config/versioned/milestones/m81/buckets/try.star

@@ -210,6 +210,7 @@ try_.chromium_linux_builder(
 try_.chromium_mac_builder(
     name = 'mac-rel',
     goma_jobs = goma.jobs.J150,
+    os = os.MAC_10_13,
     tryjob = try_.job(),
     should_exonerate_flaky_failures = True,
 )

infra/config/versioned/milestones/m83/buckets/try.star

@@ -463,6 +463,7 @@ try_.chromium_linux_builder(
 try_.chromium_mac_builder(
     name = 'mac-rel',
     goma_jobs = goma.jobs.J150,
+    os = os.MAC_10_13,
     tryjob = try_.job(),
 )
 

infra/config/versioned/trunk/buckets/try.star

@@ -471,6 +471,7 @@ try_.chromium_linux_builder(
 try_.chromium_mac_builder(
     name = 'mac-rel',
     goma_jobs = goma.jobs.J150,
+    os = os.MAC_10_13,
     tryjob = try_.job(),
 )