[test] Fix dimension for Mac DTKs

Seems after an OS upgrade the dimension Mac-11 doesn't work anymore as
swarming captures it only under Mac-11.0.

No-Try: true
Bug: chromium:1156547
Change-Id: If3f975c0aa6f8930634681c5cb05e3fdf58f322b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2579922
Auto-Submit: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71676}

infra/testing/builders.pyl

@@ -691,7 +691,7 @@
   'v8_mac_arm64_rel_ng_triggered': {
     'swarming_dimensions' : {
       'cpu': 'arm64',
-      'os': 'Mac-11',
+      'os': 'Mac-11.0',
       'pool': 'chromium.tests.mac-arm64',
     },
     'tests': [
@@ -701,7 +701,7 @@
   'v8_mac_arm64_dbg_ng_triggered': {
     'swarming_dimensions' : {
       'cpu': 'arm64',
-      'os': 'Mac-11',
+      'os': 'Mac-11.0',
       'pool': 'chromium.tests.mac-arm64',
     },
     'tests': [
@@ -711,7 +711,7 @@
   'v8_mac_arm64_full_dbg_ng_triggered': {
     'swarming_dimensions' : {
       'cpu': 'arm64',
-      'os': 'Mac-11',
+      'os': 'Mac-11.0',
       'pool': 'chromium.tests.mac-arm64',
     },
     'tests': [
@@ -1349,7 +1349,7 @@
   },
   'V8 Mac - arm64 - release': {
     'swarming_dimensions' : {
-      'os': 'Mac-11',
+      'os': 'Mac-11.0',
       'cpu': 'arm64',
       'pool': 'chromium.tests.mac-arm64',
     },